Merge branch 'js/runtime-prefix'
[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 "branch.h"
15 #include "url.h"
16 #include "submodule.h"
17 #include "string-list.h"
18 #include "sha1-array.h"
19 #include "sigchain.h"
20 #include "transport-internal.h"
21 #include "protocol.h"
22 #include "object-store.h"
23 #include "color.h"
24
25 static int transport_use_color = -1;
26 static char transport_colors[][COLOR_MAXLEN] = {
27         GIT_COLOR_RESET,
28         GIT_COLOR_RED           /* REJECTED */
29 };
30
31 enum color_transport {
32         TRANSPORT_COLOR_RESET = 0,
33         TRANSPORT_COLOR_REJECTED = 1
34 };
35
36 static int transport_color_config(void)
37 {
38         const char *keys[] = {
39                 "color.transport.reset",
40                 "color.transport.rejected"
41         }, *key = "color.transport";
42         char *value;
43         int i;
44         static int initialized;
45
46         if (initialized)
47                 return 0;
48         initialized = 1;
49
50         if (!git_config_get_string(key, &value))
51                 transport_use_color = git_config_colorbool(key, value);
52
53         if (!want_color_stderr(transport_use_color))
54                 return 0;
55
56         for (i = 0; i < ARRAY_SIZE(keys); i++)
57                 if (!git_config_get_string(keys[i], &value)) {
58                         if (!value)
59                                 return config_error_nonbool(keys[i]);
60                         if (color_parse(value, transport_colors[i]) < 0)
61                                 return -1;
62                 }
63
64         return 0;
65 }
66
67 static const char *transport_get_color(enum color_transport ix)
68 {
69         if (want_color_stderr(transport_use_color))
70                 return transport_colors[ix];
71         return "";
72 }
73
74 static void set_upstreams(struct transport *transport, struct ref *refs,
75         int pretend)
76 {
77         struct ref *ref;
78         for (ref = refs; ref; ref = ref->next) {
79                 const char *localname;
80                 const char *tmp;
81                 const char *remotename;
82                 int flag = 0;
83                 /*
84                  * Check suitability for tracking. Must be successful /
85                  * already up-to-date ref create/modify (not delete).
86                  */
87                 if (ref->status != REF_STATUS_OK &&
88                         ref->status != REF_STATUS_UPTODATE)
89                         continue;
90                 if (!ref->peer_ref)
91                         continue;
92                 if (is_null_oid(&ref->new_oid))
93                         continue;
94
95                 /* Follow symbolic refs (mainly for HEAD). */
96                 localname = ref->peer_ref->name;
97                 remotename = ref->name;
98                 tmp = resolve_ref_unsafe(localname, RESOLVE_REF_READING,
99                                          NULL, &flag);
100                 if (tmp && flag & REF_ISSYMREF &&
101                         starts_with(tmp, "refs/heads/"))
102                         localname = tmp;
103
104                 /* Both source and destination must be local branches. */
105                 if (!localname || !starts_with(localname, "refs/heads/"))
106                         continue;
107                 if (!remotename || !starts_with(remotename, "refs/heads/"))
108                         continue;
109
110                 if (!pretend)
111                         install_branch_config(BRANCH_CONFIG_VERBOSE,
112                                 localname + 11, transport->remote->name,
113                                 remotename);
114                 else
115                         printf(_("Would set upstream of '%s' to '%s' of '%s'\n"),
116                                 localname + 11, remotename + 11,
117                                 transport->remote->name);
118         }
119 }
120
121 struct bundle_transport_data {
122         int fd;
123         struct bundle_header header;
124 };
125
126 static struct ref *get_refs_from_bundle(struct transport *transport,
127                                         int for_push,
128                                         const struct argv_array *ref_prefixes)
129 {
130         struct bundle_transport_data *data = transport->data;
131         struct ref *result = NULL;
132         int i;
133
134         if (for_push)
135                 return NULL;
136
137         if (data->fd > 0)
138                 close(data->fd);
139         data->fd = read_bundle_header(transport->url, &data->header);
140         if (data->fd < 0)
141                 die ("Could not read bundle '%s'.", transport->url);
142         for (i = 0; i < data->header.references.nr; i++) {
143                 struct ref_list_entry *e = data->header.references.list + i;
144                 struct ref *ref = alloc_ref(e->name);
145                 oidcpy(&ref->old_oid, &e->oid);
146                 ref->next = result;
147                 result = ref;
148         }
149         return result;
150 }
151
152 static int fetch_refs_from_bundle(struct transport *transport,
153                                int nr_heads, struct ref **to_fetch)
154 {
155         struct bundle_transport_data *data = transport->data;
156         return unbundle(&data->header, data->fd,
157                         transport->progress ? BUNDLE_VERBOSE : 0);
158 }
159
160 static int close_bundle(struct transport *transport)
161 {
162         struct bundle_transport_data *data = transport->data;
163         if (data->fd > 0)
164                 close(data->fd);
165         free(data);
166         return 0;
167 }
168
169 struct git_transport_data {
170         struct git_transport_options options;
171         struct child_process *conn;
172         int fd[2];
173         unsigned got_remote_heads : 1;
174         enum protocol_version version;
175         struct oid_array extra_have;
176         struct oid_array shallow;
177 };
178
179 static int set_git_option(struct git_transport_options *opts,
180                           const char *name, const char *value)
181 {
182         if (!strcmp(name, TRANS_OPT_UPLOADPACK)) {
183                 opts->uploadpack = value;
184                 return 0;
185         } else if (!strcmp(name, TRANS_OPT_RECEIVEPACK)) {
186                 opts->receivepack = value;
187                 return 0;
188         } else if (!strcmp(name, TRANS_OPT_THIN)) {
189                 opts->thin = !!value;
190                 return 0;
191         } else if (!strcmp(name, TRANS_OPT_FOLLOWTAGS)) {
192                 opts->followtags = !!value;
193                 return 0;
194         } else if (!strcmp(name, TRANS_OPT_KEEP)) {
195                 opts->keep = !!value;
196                 return 0;
197         } else if (!strcmp(name, TRANS_OPT_UPDATE_SHALLOW)) {
198                 opts->update_shallow = !!value;
199                 return 0;
200         } else if (!strcmp(name, TRANS_OPT_DEPTH)) {
201                 if (!value)
202                         opts->depth = 0;
203                 else {
204                         char *end;
205                         opts->depth = strtol(value, &end, 0);
206                         if (*end)
207                                 die(_("transport: invalid depth option '%s'"), value);
208                 }
209                 return 0;
210         } else if (!strcmp(name, TRANS_OPT_DEEPEN_SINCE)) {
211                 opts->deepen_since = value;
212                 return 0;
213         } else if (!strcmp(name, TRANS_OPT_DEEPEN_NOT)) {
214                 opts->deepen_not = (const struct string_list *)value;
215                 return 0;
216         } else if (!strcmp(name, TRANS_OPT_DEEPEN_RELATIVE)) {
217                 opts->deepen_relative = !!value;
218                 return 0;
219         } else if (!strcmp(name, TRANS_OPT_FROM_PROMISOR)) {
220                 opts->from_promisor = !!value;
221                 return 0;
222         } else if (!strcmp(name, TRANS_OPT_NO_DEPENDENTS)) {
223                 opts->no_dependents = !!value;
224                 return 0;
225         } else if (!strcmp(name, TRANS_OPT_LIST_OBJECTS_FILTER)) {
226                 parse_list_objects_filter(&opts->filter_options, value);
227                 return 0;
228         }
229         return 1;
230 }
231
232 static int connect_setup(struct transport *transport, int for_push)
233 {
234         struct git_transport_data *data = transport->data;
235         int flags = transport->verbose > 0 ? CONNECT_VERBOSE : 0;
236
237         if (data->conn)
238                 return 0;
239
240         switch (transport->family) {
241         case TRANSPORT_FAMILY_ALL: break;
242         case TRANSPORT_FAMILY_IPV4: flags |= CONNECT_IPV4; break;
243         case TRANSPORT_FAMILY_IPV6: flags |= CONNECT_IPV6; break;
244         }
245
246         data->conn = git_connect(data->fd, transport->url,
247                                  for_push ? data->options.receivepack :
248                                  data->options.uploadpack,
249                                  flags);
250
251         return 0;
252 }
253
254 static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
255                                         const struct argv_array *ref_prefixes)
256 {
257         struct git_transport_data *data = transport->data;
258         struct ref *refs = NULL;
259         struct packet_reader reader;
260
261         connect_setup(transport, for_push);
262
263         packet_reader_init(&reader, data->fd[0], NULL, 0,
264                            PACKET_READ_CHOMP_NEWLINE |
265                            PACKET_READ_GENTLE_ON_EOF);
266
267         data->version = discover_version(&reader);
268         switch (data->version) {
269         case protocol_v2:
270                 get_remote_refs(data->fd[1], &reader, &refs, for_push,
271                                 ref_prefixes);
272                 break;
273         case protocol_v1:
274         case protocol_v0:
275                 get_remote_heads(&reader, &refs,
276                                  for_push ? REF_NORMAL : 0,
277                                  &data->extra_have,
278                                  &data->shallow);
279                 break;
280         case protocol_unknown_version:
281                 BUG("unknown protocol version");
282         }
283         data->got_remote_heads = 1;
284
285         return refs;
286 }
287
288 static int fetch_refs_via_pack(struct transport *transport,
289                                int nr_heads, struct ref **to_fetch)
290 {
291         int ret = 0;
292         struct git_transport_data *data = transport->data;
293         struct ref *refs = NULL;
294         char *dest = xstrdup(transport->url);
295         struct fetch_pack_args args;
296         struct ref *refs_tmp = NULL;
297
298         memset(&args, 0, sizeof(args));
299         args.uploadpack = data->options.uploadpack;
300         args.keep_pack = data->options.keep;
301         args.lock_pack = 1;
302         args.use_thin_pack = data->options.thin;
303         args.include_tag = data->options.followtags;
304         args.verbose = (transport->verbose > 1);
305         args.quiet = (transport->verbose < 0);
306         args.no_progress = !transport->progress;
307         args.depth = data->options.depth;
308         args.deepen_since = data->options.deepen_since;
309         args.deepen_not = data->options.deepen_not;
310         args.deepen_relative = data->options.deepen_relative;
311         args.check_self_contained_and_connected =
312                 data->options.check_self_contained_and_connected;
313         args.cloning = transport->cloning;
314         args.update_shallow = data->options.update_shallow;
315         args.from_promisor = data->options.from_promisor;
316         args.no_dependents = data->options.no_dependents;
317         args.filter_options = data->options.filter_options;
318         args.stateless_rpc = transport->stateless_rpc;
319
320         if (!data->got_remote_heads)
321                 refs_tmp = get_refs_via_connect(transport, 0, NULL);
322
323         switch (data->version) {
324         case protocol_v2:
325                 refs = fetch_pack(&args, data->fd, data->conn,
326                                   refs_tmp ? refs_tmp : transport->remote_refs,
327                                   dest, to_fetch, nr_heads, &data->shallow,
328                                   &transport->pack_lockfile, data->version);
329                 break;
330         case protocol_v1:
331         case protocol_v0:
332                 refs = fetch_pack(&args, data->fd, data->conn,
333                                   refs_tmp ? refs_tmp : transport->remote_refs,
334                                   dest, to_fetch, nr_heads, &data->shallow,
335                                   &transport->pack_lockfile, data->version);
336                 break;
337         case protocol_unknown_version:
338                 BUG("unknown protocol version");
339         }
340
341         close(data->fd[0]);
342         close(data->fd[1]);
343         if (finish_connect(data->conn))
344                 ret = -1;
345         data->conn = NULL;
346         data->got_remote_heads = 0;
347         data->options.self_contained_and_connected =
348                 args.self_contained_and_connected;
349
350         if (refs == NULL)
351                 ret = -1;
352         if (report_unmatched_refs(to_fetch, nr_heads))
353                 ret = -1;
354
355         free_refs(refs_tmp);
356         free_refs(refs);
357         free(dest);
358         return ret;
359 }
360
361 static int push_had_errors(struct ref *ref)
362 {
363         for (; ref; ref = ref->next) {
364                 switch (ref->status) {
365                 case REF_STATUS_NONE:
366                 case REF_STATUS_UPTODATE:
367                 case REF_STATUS_OK:
368                         break;
369                 default:
370                         return 1;
371                 }
372         }
373         return 0;
374 }
375
376 int transport_refs_pushed(struct ref *ref)
377 {
378         for (; ref; ref = ref->next) {
379                 switch(ref->status) {
380                 case REF_STATUS_NONE:
381                 case REF_STATUS_UPTODATE:
382                         break;
383                 default:
384                         return 1;
385                 }
386         }
387         return 0;
388 }
389
390 void transport_update_tracking_ref(struct remote *remote, struct ref *ref, int verbose)
391 {
392         struct refspec rs;
393
394         if (ref->status != REF_STATUS_OK && ref->status != REF_STATUS_UPTODATE)
395                 return;
396
397         rs.src = ref->name;
398         rs.dst = NULL;
399
400         if (!remote_find_tracking(remote, &rs)) {
401                 if (verbose)
402                         fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
403                 if (ref->deletion) {
404                         delete_ref(NULL, rs.dst, NULL, 0);
405                 } else
406                         update_ref("update by push", rs.dst, &ref->new_oid,
407                                    NULL, 0, 0);
408                 free(rs.dst);
409         }
410 }
411
412 static void print_ref_status(char flag, const char *summary,
413                              struct ref *to, struct ref *from, const char *msg,
414                              int porcelain, int summary_width)
415 {
416         if (porcelain) {
417                 if (from)
418                         fprintf(stdout, "%c\t%s:%s\t", flag, from->name, to->name);
419                 else
420                         fprintf(stdout, "%c\t:%s\t", flag, to->name);
421                 if (msg)
422                         fprintf(stdout, "%s (%s)\n", summary, msg);
423                 else
424                         fprintf(stdout, "%s\n", summary);
425         } else {
426                 const char *red = "", *reset = "";
427                 if (push_had_errors(to)) {
428                         red = transport_get_color(TRANSPORT_COLOR_REJECTED);
429                         reset = transport_get_color(TRANSPORT_COLOR_RESET);
430                 }
431                 fprintf(stderr, " %s%c %-*s%s ", red, flag, summary_width,
432                         summary, reset);
433                 if (from)
434                         fprintf(stderr, "%s -> %s", prettify_refname(from->name), prettify_refname(to->name));
435                 else
436                         fputs(prettify_refname(to->name), stderr);
437                 if (msg) {
438                         fputs(" (", stderr);
439                         fputs(msg, stderr);
440                         fputc(')', stderr);
441                 }
442                 fputc('\n', stderr);
443         }
444 }
445
446 static void print_ok_ref_status(struct ref *ref, int porcelain, int summary_width)
447 {
448         if (ref->deletion)
449                 print_ref_status('-', "[deleted]", ref, NULL, NULL,
450                                  porcelain, summary_width);
451         else if (is_null_oid(&ref->old_oid))
452                 print_ref_status('*',
453                         (starts_with(ref->name, "refs/tags/") ? "[new tag]" :
454                         "[new branch]"),
455                         ref, ref->peer_ref, NULL, porcelain, summary_width);
456         else {
457                 struct strbuf quickref = STRBUF_INIT;
458                 char type;
459                 const char *msg;
460
461                 strbuf_add_unique_abbrev(&quickref, &ref->old_oid,
462                                          DEFAULT_ABBREV);
463                 if (ref->forced_update) {
464                         strbuf_addstr(&quickref, "...");
465                         type = '+';
466                         msg = "forced update";
467                 } else {
468                         strbuf_addstr(&quickref, "..");
469                         type = ' ';
470                         msg = NULL;
471                 }
472                 strbuf_add_unique_abbrev(&quickref, &ref->new_oid,
473                                          DEFAULT_ABBREV);
474
475                 print_ref_status(type, quickref.buf, ref, ref->peer_ref, msg,
476                                  porcelain, summary_width);
477                 strbuf_release(&quickref);
478         }
479 }
480
481 static int print_one_push_status(struct ref *ref, const char *dest, int count,
482                                  int porcelain, int summary_width)
483 {
484         if (!count) {
485                 char *url = transport_anonymize_url(dest);
486                 fprintf(porcelain ? stdout : stderr, "To %s\n", url);
487                 free(url);
488         }
489
490         switch(ref->status) {
491         case REF_STATUS_NONE:
492                 print_ref_status('X', "[no match]", ref, NULL, NULL,
493                                  porcelain, summary_width);
494                 break;
495         case REF_STATUS_REJECT_NODELETE:
496                 print_ref_status('!', "[rejected]", ref, NULL,
497                                  "remote does not support deleting refs",
498                                  porcelain, summary_width);
499                 break;
500         case REF_STATUS_UPTODATE:
501                 print_ref_status('=', "[up to date]", ref,
502                                  ref->peer_ref, NULL, porcelain, summary_width);
503                 break;
504         case REF_STATUS_REJECT_NONFASTFORWARD:
505                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
506                                  "non-fast-forward", porcelain, summary_width);
507                 break;
508         case REF_STATUS_REJECT_ALREADY_EXISTS:
509                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
510                                  "already exists", porcelain, summary_width);
511                 break;
512         case REF_STATUS_REJECT_FETCH_FIRST:
513                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
514                                  "fetch first", porcelain, summary_width);
515                 break;
516         case REF_STATUS_REJECT_NEEDS_FORCE:
517                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
518                                  "needs force", porcelain, summary_width);
519                 break;
520         case REF_STATUS_REJECT_STALE:
521                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
522                                  "stale info", porcelain, summary_width);
523                 break;
524         case REF_STATUS_REJECT_SHALLOW:
525                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
526                                  "new shallow roots not allowed",
527                                  porcelain, summary_width);
528                 break;
529         case REF_STATUS_REMOTE_REJECT:
530                 print_ref_status('!', "[remote rejected]", ref,
531                                  ref->deletion ? NULL : ref->peer_ref,
532                                  ref->remote_status, porcelain, summary_width);
533                 break;
534         case REF_STATUS_EXPECTING_REPORT:
535                 print_ref_status('!', "[remote failure]", ref,
536                                  ref->deletion ? NULL : ref->peer_ref,
537                                  "remote failed to report status",
538                                  porcelain, summary_width);
539                 break;
540         case REF_STATUS_ATOMIC_PUSH_FAILED:
541                 print_ref_status('!', "[rejected]", ref, ref->peer_ref,
542                                  "atomic push failed", porcelain, summary_width);
543                 break;
544         case REF_STATUS_OK:
545                 print_ok_ref_status(ref, porcelain, summary_width);
546                 break;
547         }
548
549         return 1;
550 }
551
552 static int measure_abbrev(const struct object_id *oid, int sofar)
553 {
554         char hex[GIT_MAX_HEXSZ + 1];
555         int w = find_unique_abbrev_r(hex, oid, DEFAULT_ABBREV);
556
557         return (w < sofar) ? sofar : w;
558 }
559
560 int transport_summary_width(const struct ref *refs)
561 {
562         int maxw = -1;
563
564         for (; refs; refs = refs->next) {
565                 maxw = measure_abbrev(&refs->old_oid, maxw);
566                 maxw = measure_abbrev(&refs->new_oid, maxw);
567         }
568         if (maxw < 0)
569                 maxw = FALLBACK_DEFAULT_ABBREV;
570         return (2 * maxw + 3);
571 }
572
573 void transport_print_push_status(const char *dest, struct ref *refs,
574                                   int verbose, int porcelain, unsigned int *reject_reasons)
575 {
576         struct ref *ref;
577         int n = 0;
578         char *head;
579         int summary_width = transport_summary_width(refs);
580
581         if (transport_color_config() < 0)
582                 warning(_("could not parse transport.color.* config"));
583
584         head = resolve_refdup("HEAD", RESOLVE_REF_READING, NULL, NULL);
585
586         if (verbose) {
587                 for (ref = refs; ref; ref = ref->next)
588                         if (ref->status == REF_STATUS_UPTODATE)
589                                 n += print_one_push_status(ref, dest, n,
590                                                            porcelain, summary_width);
591         }
592
593         for (ref = refs; ref; ref = ref->next)
594                 if (ref->status == REF_STATUS_OK)
595                         n += print_one_push_status(ref, dest, n,
596                                                    porcelain, summary_width);
597
598         *reject_reasons = 0;
599         for (ref = refs; ref; ref = ref->next) {
600                 if (ref->status != REF_STATUS_NONE &&
601                     ref->status != REF_STATUS_UPTODATE &&
602                     ref->status != REF_STATUS_OK)
603                         n += print_one_push_status(ref, dest, n,
604                                                    porcelain, summary_width);
605                 if (ref->status == REF_STATUS_REJECT_NONFASTFORWARD) {
606                         if (head != NULL && !strcmp(head, ref->name))
607                                 *reject_reasons |= REJECT_NON_FF_HEAD;
608                         else
609                                 *reject_reasons |= REJECT_NON_FF_OTHER;
610                 } else if (ref->status == REF_STATUS_REJECT_ALREADY_EXISTS) {
611                         *reject_reasons |= REJECT_ALREADY_EXISTS;
612                 } else if (ref->status == REF_STATUS_REJECT_FETCH_FIRST) {
613                         *reject_reasons |= REJECT_FETCH_FIRST;
614                 } else if (ref->status == REF_STATUS_REJECT_NEEDS_FORCE) {
615                         *reject_reasons |= REJECT_NEEDS_FORCE;
616                 }
617         }
618         free(head);
619 }
620
621 void transport_verify_remote_names(int nr_heads, const char **heads)
622 {
623         int i;
624
625         for (i = 0; i < nr_heads; i++) {
626                 const char *local = heads[i];
627                 const char *remote = strrchr(heads[i], ':');
628
629                 if (*local == '+')
630                         local++;
631
632                 /* A matching refspec is okay.  */
633                 if (remote == local && remote[1] == '\0')
634                         continue;
635
636                 remote = remote ? (remote + 1) : local;
637                 if (check_refname_format(remote,
638                                 REFNAME_ALLOW_ONELEVEL|REFNAME_REFSPEC_PATTERN))
639                         die("remote part of refspec is not a valid name in %s",
640                                 heads[i]);
641         }
642 }
643
644 static int git_transport_push(struct transport *transport, struct ref *remote_refs, int flags)
645 {
646         struct git_transport_data *data = transport->data;
647         struct send_pack_args args;
648         int ret = 0;
649
650         if (transport_color_config() < 0)
651                 return -1;
652
653         if (!data->got_remote_heads)
654                 get_refs_via_connect(transport, 1, NULL);
655
656         memset(&args, 0, sizeof(args));
657         args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
658         args.force_update = !!(flags & TRANSPORT_PUSH_FORCE);
659         args.use_thin_pack = data->options.thin;
660         args.verbose = (transport->verbose > 0);
661         args.quiet = (transport->verbose < 0);
662         args.progress = transport->progress;
663         args.dry_run = !!(flags & TRANSPORT_PUSH_DRY_RUN);
664         args.porcelain = !!(flags & TRANSPORT_PUSH_PORCELAIN);
665         args.atomic = !!(flags & TRANSPORT_PUSH_ATOMIC);
666         args.push_options = transport->push_options;
667         args.url = transport->url;
668
669         if (flags & TRANSPORT_PUSH_CERT_ALWAYS)
670                 args.push_cert = SEND_PACK_PUSH_CERT_ALWAYS;
671         else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED)
672                 args.push_cert = SEND_PACK_PUSH_CERT_IF_ASKED;
673         else
674                 args.push_cert = SEND_PACK_PUSH_CERT_NEVER;
675
676         switch (data->version) {
677         case protocol_v2:
678                 die("support for protocol v2 not implemented yet");
679                 break;
680         case protocol_v1:
681         case protocol_v0:
682                 ret = send_pack(&args, data->fd, data->conn, remote_refs,
683                                 &data->extra_have);
684                 break;
685         case protocol_unknown_version:
686                 BUG("unknown protocol version");
687         }
688
689         close(data->fd[1]);
690         close(data->fd[0]);
691         ret |= finish_connect(data->conn);
692         data->conn = NULL;
693         data->got_remote_heads = 0;
694
695         return ret;
696 }
697
698 static int connect_git(struct transport *transport, const char *name,
699                        const char *executable, int fd[2])
700 {
701         struct git_transport_data *data = transport->data;
702         data->conn = git_connect(data->fd, transport->url,
703                                  executable, 0);
704         fd[0] = data->fd[0];
705         fd[1] = data->fd[1];
706         return 0;
707 }
708
709 static int disconnect_git(struct transport *transport)
710 {
711         struct git_transport_data *data = transport->data;
712         if (data->conn) {
713                 if (data->got_remote_heads)
714                         packet_flush(data->fd[1]);
715                 close(data->fd[0]);
716                 close(data->fd[1]);
717                 finish_connect(data->conn);
718         }
719
720         free(data);
721         return 0;
722 }
723
724 static struct transport_vtable taken_over_vtable = {
725         NULL,
726         get_refs_via_connect,
727         fetch_refs_via_pack,
728         git_transport_push,
729         NULL,
730         disconnect_git
731 };
732
733 void transport_take_over(struct transport *transport,
734                          struct child_process *child)
735 {
736         struct git_transport_data *data;
737
738         if (!transport->smart_options)
739                 die("BUG: taking over transport requires non-NULL "
740                     "smart_options field.");
741
742         data = xcalloc(1, sizeof(*data));
743         data->options = *transport->smart_options;
744         data->conn = child;
745         data->fd[0] = data->conn->out;
746         data->fd[1] = data->conn->in;
747         data->got_remote_heads = 0;
748         transport->data = data;
749
750         transport->vtable = &taken_over_vtable;
751         transport->smart_options = &(data->options);
752
753         transport->cannot_reuse = 1;
754 }
755
756 static int is_file(const char *url)
757 {
758         struct stat buf;
759         if (stat(url, &buf))
760                 return 0;
761         return S_ISREG(buf.st_mode);
762 }
763
764 static int external_specification_len(const char *url)
765 {
766         return strchr(url, ':') - url;
767 }
768
769 static const struct string_list *protocol_whitelist(void)
770 {
771         static int enabled = -1;
772         static struct string_list allowed = STRING_LIST_INIT_DUP;
773
774         if (enabled < 0) {
775                 const char *v = getenv("GIT_ALLOW_PROTOCOL");
776                 if (v) {
777                         string_list_split(&allowed, v, ':', -1);
778                         string_list_sort(&allowed);
779                         enabled = 1;
780                 } else {
781                         enabled = 0;
782                 }
783         }
784
785         return enabled ? &allowed : NULL;
786 }
787
788 enum protocol_allow_config {
789         PROTOCOL_ALLOW_NEVER = 0,
790         PROTOCOL_ALLOW_USER_ONLY,
791         PROTOCOL_ALLOW_ALWAYS
792 };
793
794 static enum protocol_allow_config parse_protocol_config(const char *key,
795                                                         const char *value)
796 {
797         if (!strcasecmp(value, "always"))
798                 return PROTOCOL_ALLOW_ALWAYS;
799         else if (!strcasecmp(value, "never"))
800                 return PROTOCOL_ALLOW_NEVER;
801         else if (!strcasecmp(value, "user"))
802                 return PROTOCOL_ALLOW_USER_ONLY;
803
804         die("unknown value for config '%s': %s", key, value);
805 }
806
807 static enum protocol_allow_config get_protocol_config(const char *type)
808 {
809         char *key = xstrfmt("protocol.%s.allow", type);
810         char *value;
811
812         /* first check the per-protocol config */
813         if (!git_config_get_string(key, &value)) {
814                 enum protocol_allow_config ret =
815                         parse_protocol_config(key, value);
816                 free(key);
817                 free(value);
818                 return ret;
819         }
820         free(key);
821
822         /* if defined, fallback to user-defined default for unknown protocols */
823         if (!git_config_get_string("protocol.allow", &value)) {
824                 enum protocol_allow_config ret =
825                         parse_protocol_config("protocol.allow", value);
826                 free(value);
827                 return ret;
828         }
829
830         /* fallback to built-in defaults */
831         /* known safe */
832         if (!strcmp(type, "http") ||
833             !strcmp(type, "https") ||
834             !strcmp(type, "git") ||
835             !strcmp(type, "ssh") ||
836             !strcmp(type, "file"))
837                 return PROTOCOL_ALLOW_ALWAYS;
838
839         /* known scary; err on the side of caution */
840         if (!strcmp(type, "ext"))
841                 return PROTOCOL_ALLOW_NEVER;
842
843         /* unknown; by default let them be used only directly by the user */
844         return PROTOCOL_ALLOW_USER_ONLY;
845 }
846
847 int is_transport_allowed(const char *type, int from_user)
848 {
849         const struct string_list *whitelist = protocol_whitelist();
850         if (whitelist)
851                 return string_list_has_string(whitelist, type);
852
853         switch (get_protocol_config(type)) {
854         case PROTOCOL_ALLOW_ALWAYS:
855                 return 1;
856         case PROTOCOL_ALLOW_NEVER:
857                 return 0;
858         case PROTOCOL_ALLOW_USER_ONLY:
859                 if (from_user < 0)
860                         from_user = git_env_bool("GIT_PROTOCOL_FROM_USER", 1);
861                 return from_user;
862         }
863
864         die("BUG: invalid protocol_allow_config type");
865 }
866
867 void transport_check_allowed(const char *type)
868 {
869         if (!is_transport_allowed(type, -1))
870                 die("transport '%s' not allowed", type);
871 }
872
873 static struct transport_vtable bundle_vtable = {
874         NULL,
875         get_refs_from_bundle,
876         fetch_refs_from_bundle,
877         NULL,
878         NULL,
879         close_bundle
880 };
881
882 static struct transport_vtable builtin_smart_vtable = {
883         NULL,
884         get_refs_via_connect,
885         fetch_refs_via_pack,
886         git_transport_push,
887         connect_git,
888         disconnect_git
889 };
890
891 struct transport *transport_get(struct remote *remote, const char *url)
892 {
893         const char *helper;
894         struct transport *ret = xcalloc(1, sizeof(*ret));
895
896         ret->progress = isatty(2);
897
898         if (!remote)
899                 die("No remote provided to transport_get()");
900
901         ret->got_remote_refs = 0;
902         ret->remote = remote;
903         helper = remote->foreign_vcs;
904
905         if (!url && remote->url)
906                 url = remote->url[0];
907         ret->url = url;
908
909         /* maybe it is a foreign URL? */
910         if (url) {
911                 const char *p = url;
912
913                 while (is_urlschemechar(p == url, *p))
914                         p++;
915                 if (starts_with(p, "::"))
916                         helper = xstrndup(url, p - url);
917         }
918
919         if (helper) {
920                 transport_helper_init(ret, helper);
921         } else if (starts_with(url, "rsync:")) {
922                 die("git-over-rsync is no longer supported");
923         } else if (url_is_local_not_ssh(url) && is_file(url) && is_bundle(url, 1)) {
924                 struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
925                 transport_check_allowed("file");
926                 ret->data = data;
927                 ret->vtable = &bundle_vtable;
928                 ret->smart_options = NULL;
929         } else if (!is_url(url)
930                 || starts_with(url, "file://")
931                 || starts_with(url, "git://")
932                 || starts_with(url, "ssh://")
933                 || starts_with(url, "git+ssh://") /* deprecated - do not use */
934                 || starts_with(url, "ssh+git://") /* deprecated - do not use */
935                 ) {
936                 /*
937                  * These are builtin smart transports; "allowed" transports
938                  * will be checked individually in git_connect.
939                  */
940                 struct git_transport_data *data = xcalloc(1, sizeof(*data));
941                 ret->data = data;
942                 ret->vtable = &builtin_smart_vtable;
943                 ret->smart_options = &(data->options);
944
945                 data->conn = NULL;
946                 data->got_remote_heads = 0;
947         } else {
948                 /* Unknown protocol in URL. Pass to external handler. */
949                 int len = external_specification_len(url);
950                 char *handler = xmemdupz(url, len);
951                 transport_helper_init(ret, handler);
952         }
953
954         if (ret->smart_options) {
955                 ret->smart_options->thin = 1;
956                 ret->smart_options->uploadpack = "git-upload-pack";
957                 if (remote->uploadpack)
958                         ret->smart_options->uploadpack = remote->uploadpack;
959                 ret->smart_options->receivepack = "git-receive-pack";
960                 if (remote->receivepack)
961                         ret->smart_options->receivepack = remote->receivepack;
962         }
963
964         return ret;
965 }
966
967 int transport_set_option(struct transport *transport,
968                          const char *name, const char *value)
969 {
970         int git_reports = 1, protocol_reports = 1;
971
972         if (transport->smart_options)
973                 git_reports = set_git_option(transport->smart_options,
974                                              name, value);
975
976         if (transport->vtable->set_option)
977                 protocol_reports = transport->vtable->set_option(transport,
978                                                                  name, value);
979
980         /* If either report is 0, report 0 (success). */
981         if (!git_reports || !protocol_reports)
982                 return 0;
983         /* If either reports -1 (invalid value), report -1. */
984         if ((git_reports == -1) || (protocol_reports == -1))
985                 return -1;
986         /* Otherwise if both report unknown, report unknown. */
987         return 1;
988 }
989
990 void transport_set_verbosity(struct transport *transport, int verbosity,
991         int force_progress)
992 {
993         if (verbosity >= 1)
994                 transport->verbose = verbosity <= 3 ? verbosity : 3;
995         if (verbosity < 0)
996                 transport->verbose = -1;
997
998         /**
999          * Rules used to determine whether to report progress (processing aborts
1000          * when a rule is satisfied):
1001          *
1002          *   . Report progress, if force_progress is 1 (ie. --progress).
1003          *   . Don't report progress, if force_progress is 0 (ie. --no-progress).
1004          *   . Don't report progress, if verbosity < 0 (ie. -q/--quiet ).
1005          *   . Report progress if isatty(2) is 1.
1006          **/
1007         if (force_progress >= 0)
1008                 transport->progress = !!force_progress;
1009         else
1010                 transport->progress = verbosity >= 0 && isatty(2);
1011 }
1012
1013 static void die_with_unpushed_submodules(struct string_list *needs_pushing)
1014 {
1015         int i;
1016
1017         fprintf(stderr, _("The following submodule paths contain changes that can\n"
1018                         "not be found on any remote:\n"));
1019         for (i = 0; i < needs_pushing->nr; i++)
1020                 fprintf(stderr, "  %s\n", needs_pushing->items[i].string);
1021         fprintf(stderr, _("\nPlease try\n\n"
1022                           "     git push --recurse-submodules=on-demand\n\n"
1023                           "or cd to the path and use\n\n"
1024                           "     git push\n\n"
1025                           "to push them to a remote.\n\n"));
1026
1027         string_list_clear(needs_pushing, 0);
1028
1029         die(_("Aborting."));
1030 }
1031
1032 static int run_pre_push_hook(struct transport *transport,
1033                              struct ref *remote_refs)
1034 {
1035         int ret = 0, x;
1036         struct ref *r;
1037         struct child_process proc = CHILD_PROCESS_INIT;
1038         struct strbuf buf;
1039         const char *argv[4];
1040
1041         if (!(argv[0] = find_hook("pre-push")))
1042                 return 0;
1043
1044         argv[1] = transport->remote->name;
1045         argv[2] = transport->url;
1046         argv[3] = NULL;
1047
1048         proc.argv = argv;
1049         proc.in = -1;
1050
1051         if (start_command(&proc)) {
1052                 finish_command(&proc);
1053                 return -1;
1054         }
1055
1056         sigchain_push(SIGPIPE, SIG_IGN);
1057
1058         strbuf_init(&buf, 256);
1059
1060         for (r = remote_refs; r; r = r->next) {
1061                 if (!r->peer_ref) continue;
1062                 if (r->status == REF_STATUS_REJECT_NONFASTFORWARD) continue;
1063                 if (r->status == REF_STATUS_REJECT_STALE) continue;
1064                 if (r->status == REF_STATUS_UPTODATE) continue;
1065
1066                 strbuf_reset(&buf);
1067                 strbuf_addf( &buf, "%s %s %s %s\n",
1068                          r->peer_ref->name, oid_to_hex(&r->new_oid),
1069                          r->name, oid_to_hex(&r->old_oid));
1070
1071                 if (write_in_full(proc.in, buf.buf, buf.len) < 0) {
1072                         /* We do not mind if a hook does not read all refs. */
1073                         if (errno != EPIPE)
1074                                 ret = -1;
1075                         break;
1076                 }
1077         }
1078
1079         strbuf_release(&buf);
1080
1081         x = close(proc.in);
1082         if (!ret)
1083                 ret = x;
1084
1085         sigchain_pop(SIGPIPE);
1086
1087         x = finish_command(&proc);
1088         if (!ret)
1089                 ret = x;
1090
1091         return ret;
1092 }
1093
1094 int transport_push(struct transport *transport,
1095                    int refspec_nr, const char **refspec, int flags,
1096                    unsigned int *reject_reasons)
1097 {
1098         *reject_reasons = 0;
1099         transport_verify_remote_names(refspec_nr, refspec);
1100
1101         if (transport_color_config() < 0)
1102                 return -1;
1103
1104         if (transport->vtable->push_refs) {
1105                 struct ref *remote_refs;
1106                 struct ref *local_refs = get_local_heads();
1107                 int match_flags = MATCH_REFS_NONE;
1108                 int verbose = (transport->verbose > 0);
1109                 int quiet = (transport->verbose < 0);
1110                 int porcelain = flags & TRANSPORT_PUSH_PORCELAIN;
1111                 int pretend = flags & TRANSPORT_PUSH_DRY_RUN;
1112                 int push_ret, ret, err;
1113                 struct refspec *tmp_rs;
1114                 struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
1115                 int i;
1116
1117                 if (check_push_refs(local_refs, refspec_nr, refspec) < 0)
1118                         return -1;
1119
1120                 tmp_rs = parse_push_refspec(refspec_nr, refspec);
1121                 for (i = 0; i < refspec_nr; i++) {
1122                         const char *prefix = NULL;
1123
1124                         if (tmp_rs[i].dst)
1125                                 prefix = tmp_rs[i].dst;
1126                         else if (tmp_rs[i].src && !tmp_rs[i].exact_sha1)
1127                                 prefix = tmp_rs[i].src;
1128
1129                         if (prefix) {
1130                                 const char *glob = strchr(prefix, '*');
1131                                 if (glob)
1132                                         argv_array_pushf(&ref_prefixes, "%.*s",
1133                                                          (int)(glob - prefix),
1134                                                          prefix);
1135                                 else
1136                                         expand_ref_prefix(&ref_prefixes, prefix);
1137                         }
1138                 }
1139
1140                 remote_refs = transport->vtable->get_refs_list(transport, 1,
1141                                                                &ref_prefixes);
1142
1143                 argv_array_clear(&ref_prefixes);
1144                 free_refspec(refspec_nr, tmp_rs);
1145
1146                 if (flags & TRANSPORT_PUSH_ALL)
1147                         match_flags |= MATCH_REFS_ALL;
1148                 if (flags & TRANSPORT_PUSH_MIRROR)
1149                         match_flags |= MATCH_REFS_MIRROR;
1150                 if (flags & TRANSPORT_PUSH_PRUNE)
1151                         match_flags |= MATCH_REFS_PRUNE;
1152                 if (flags & TRANSPORT_PUSH_FOLLOW_TAGS)
1153                         match_flags |= MATCH_REFS_FOLLOW_TAGS;
1154
1155                 if (match_push_refs(local_refs, &remote_refs,
1156                                     refspec_nr, refspec, match_flags)) {
1157                         return -1;
1158                 }
1159
1160                 if (transport->smart_options &&
1161                     transport->smart_options->cas &&
1162                     !is_empty_cas(transport->smart_options->cas))
1163                         apply_push_cas(transport->smart_options->cas,
1164                                        transport->remote, remote_refs);
1165
1166                 set_ref_status_for_push(remote_refs,
1167                         flags & TRANSPORT_PUSH_MIRROR,
1168                         flags & TRANSPORT_PUSH_FORCE);
1169
1170                 if (!(flags & TRANSPORT_PUSH_NO_HOOK))
1171                         if (run_pre_push_hook(transport, remote_refs))
1172                                 return -1;
1173
1174                 if ((flags & (TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND |
1175                               TRANSPORT_RECURSE_SUBMODULES_ONLY)) &&
1176                     !is_bare_repository()) {
1177                         struct ref *ref = remote_refs;
1178                         struct oid_array commits = OID_ARRAY_INIT;
1179
1180                         for (; ref; ref = ref->next)
1181                                 if (!is_null_oid(&ref->new_oid))
1182                                         oid_array_append(&commits,
1183                                                           &ref->new_oid);
1184
1185                         if (!push_unpushed_submodules(&commits,
1186                                                       transport->remote,
1187                                                       refspec, refspec_nr,
1188                                                       transport->push_options,
1189                                                       pretend)) {
1190                                 oid_array_clear(&commits);
1191                                 die("Failed to push all needed submodules!");
1192                         }
1193                         oid_array_clear(&commits);
1194                 }
1195
1196                 if (((flags & TRANSPORT_RECURSE_SUBMODULES_CHECK) ||
1197                      ((flags & (TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND |
1198                                 TRANSPORT_RECURSE_SUBMODULES_ONLY)) &&
1199                       !pretend)) && !is_bare_repository()) {
1200                         struct ref *ref = remote_refs;
1201                         struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1202                         struct oid_array commits = OID_ARRAY_INIT;
1203
1204                         for (; ref; ref = ref->next)
1205                                 if (!is_null_oid(&ref->new_oid))
1206                                         oid_array_append(&commits,
1207                                                           &ref->new_oid);
1208
1209                         if (find_unpushed_submodules(&commits, transport->remote->name,
1210                                                 &needs_pushing)) {
1211                                 oid_array_clear(&commits);
1212                                 die_with_unpushed_submodules(&needs_pushing);
1213                         }
1214                         string_list_clear(&needs_pushing, 0);
1215                         oid_array_clear(&commits);
1216                 }
1217
1218                 if (!(flags & TRANSPORT_RECURSE_SUBMODULES_ONLY))
1219                         push_ret = transport->vtable->push_refs(transport, remote_refs, flags);
1220                 else
1221                         push_ret = 0;
1222                 err = push_had_errors(remote_refs);
1223                 ret = push_ret | err;
1224
1225                 if (!quiet || err)
1226                         transport_print_push_status(transport->url, remote_refs,
1227                                         verbose | porcelain, porcelain,
1228                                         reject_reasons);
1229
1230                 if (flags & TRANSPORT_PUSH_SET_UPSTREAM)
1231                         set_upstreams(transport, remote_refs, pretend);
1232
1233                 if (!(flags & (TRANSPORT_PUSH_DRY_RUN |
1234                                TRANSPORT_RECURSE_SUBMODULES_ONLY))) {
1235                         struct ref *ref;
1236                         for (ref = remote_refs; ref; ref = ref->next)
1237                                 transport_update_tracking_ref(transport->remote, ref, verbose);
1238                 }
1239
1240                 if (porcelain && !push_ret)
1241                         puts("Done");
1242                 else if (!quiet && !ret && !transport_refs_pushed(remote_refs))
1243                         fprintf(stderr, "Everything up-to-date\n");
1244
1245                 return ret;
1246         }
1247         return 1;
1248 }
1249
1250 const struct ref *transport_get_remote_refs(struct transport *transport,
1251                                             const struct argv_array *ref_prefixes)
1252 {
1253         if (!transport->got_remote_refs) {
1254                 transport->remote_refs =
1255                         transport->vtable->get_refs_list(transport, 0,
1256                                                          ref_prefixes);
1257                 transport->got_remote_refs = 1;
1258         }
1259
1260         return transport->remote_refs;
1261 }
1262
1263 int transport_fetch_refs(struct transport *transport, struct ref *refs)
1264 {
1265         int rc;
1266         int nr_heads = 0, nr_alloc = 0, nr_refs = 0;
1267         struct ref **heads = NULL;
1268         struct ref *rm;
1269
1270         for (rm = refs; rm; rm = rm->next) {
1271                 nr_refs++;
1272                 if (rm->peer_ref &&
1273                     !is_null_oid(&rm->old_oid) &&
1274                     !oidcmp(&rm->peer_ref->old_oid, &rm->old_oid))
1275                         continue;
1276                 ALLOC_GROW(heads, nr_heads + 1, nr_alloc);
1277                 heads[nr_heads++] = rm;
1278         }
1279
1280         if (!nr_heads) {
1281                 /*
1282                  * When deepening of a shallow repository is requested,
1283                  * then local and remote refs are likely to still be equal.
1284                  * Just feed them all to the fetch method in that case.
1285                  * This condition shouldn't be met in a non-deepening fetch
1286                  * (see builtin/fetch.c:quickfetch()).
1287                  */
1288                 ALLOC_ARRAY(heads, nr_refs);
1289                 for (rm = refs; rm; rm = rm->next)
1290                         heads[nr_heads++] = rm;
1291         }
1292
1293         rc = transport->vtable->fetch(transport, nr_heads, heads);
1294
1295         free(heads);
1296         return rc;
1297 }
1298
1299 void transport_unlock_pack(struct transport *transport)
1300 {
1301         if (transport->pack_lockfile) {
1302                 unlink_or_warn(transport->pack_lockfile);
1303                 FREE_AND_NULL(transport->pack_lockfile);
1304         }
1305 }
1306
1307 int transport_connect(struct transport *transport, const char *name,
1308                       const char *exec, int fd[2])
1309 {
1310         if (transport->vtable->connect)
1311                 return transport->vtable->connect(transport, name, exec, fd);
1312         else
1313                 die("Operation not supported by protocol");
1314 }
1315
1316 int transport_disconnect(struct transport *transport)
1317 {
1318         int ret = 0;
1319         if (transport->vtable->disconnect)
1320                 ret = transport->vtable->disconnect(transport);
1321         free(transport);
1322         return ret;
1323 }
1324
1325 /*
1326  * Strip username (and password) from a URL and return
1327  * it in a newly allocated string.
1328  */
1329 char *transport_anonymize_url(const char *url)
1330 {
1331         char *scheme_prefix, *anon_part;
1332         size_t anon_len, prefix_len = 0;
1333
1334         anon_part = strchr(url, '@');
1335         if (url_is_local_not_ssh(url) || !anon_part)
1336                 goto literal_copy;
1337
1338         anon_len = strlen(++anon_part);
1339         scheme_prefix = strstr(url, "://");
1340         if (!scheme_prefix) {
1341                 if (!strchr(anon_part, ':'))
1342                         /* cannot be "me@there:/path/name" */
1343                         goto literal_copy;
1344         } else {
1345                 const char *cp;
1346                 /* make sure scheme is reasonable */
1347                 for (cp = url; cp < scheme_prefix; cp++) {
1348                         switch (*cp) {
1349                                 /* RFC 1738 2.1 */
1350                         case '+': case '.': case '-':
1351                                 break; /* ok */
1352                         default:
1353                                 if (isalnum(*cp))
1354                                         break;
1355                                 /* it isn't */
1356                                 goto literal_copy;
1357                         }
1358                 }
1359                 /* @ past the first slash does not count */
1360                 cp = strchr(scheme_prefix + 3, '/');
1361                 if (cp && cp < anon_part)
1362                         goto literal_copy;
1363                 prefix_len = scheme_prefix - url + 3;
1364         }
1365         return xstrfmt("%.*s%.*s", (int)prefix_len, url,
1366                        (int)anon_len, anon_part);
1367 literal_copy:
1368         return xstrdup(url);
1369 }
1370
1371 static void read_alternate_refs(const char *path,
1372                                 alternate_ref_fn *cb,
1373                                 void *data)
1374 {
1375         struct child_process cmd = CHILD_PROCESS_INIT;
1376         struct strbuf line = STRBUF_INIT;
1377         FILE *fh;
1378
1379         cmd.git_cmd = 1;
1380         argv_array_pushf(&cmd.args, "--git-dir=%s", path);
1381         argv_array_push(&cmd.args, "for-each-ref");
1382         argv_array_push(&cmd.args, "--format=%(objectname) %(refname)");
1383         cmd.env = local_repo_env;
1384         cmd.out = -1;
1385
1386         if (start_command(&cmd))
1387                 return;
1388
1389         fh = xfdopen(cmd.out, "r");
1390         while (strbuf_getline_lf(&line, fh) != EOF) {
1391                 struct object_id oid;
1392
1393                 if (get_oid_hex(line.buf, &oid) ||
1394                     line.buf[GIT_SHA1_HEXSZ] != ' ') {
1395                         warning("invalid line while parsing alternate refs: %s",
1396                                 line.buf);
1397                         break;
1398                 }
1399
1400                 cb(line.buf + GIT_SHA1_HEXSZ + 1, &oid, data);
1401         }
1402
1403         fclose(fh);
1404         finish_command(&cmd);
1405 }
1406
1407 struct alternate_refs_data {
1408         alternate_ref_fn *fn;
1409         void *data;
1410 };
1411
1412 static int refs_from_alternate_cb(struct alternate_object_database *e,
1413                                   void *data)
1414 {
1415         struct strbuf path = STRBUF_INIT;
1416         size_t base_len;
1417         struct alternate_refs_data *cb = data;
1418
1419         if (!strbuf_realpath(&path, e->path, 0))
1420                 goto out;
1421         if (!strbuf_strip_suffix(&path, "/objects"))
1422                 goto out;
1423         base_len = path.len;
1424
1425         /* Is this a git repository with refs? */
1426         strbuf_addstr(&path, "/refs");
1427         if (!is_directory(path.buf))
1428                 goto out;
1429         strbuf_setlen(&path, base_len);
1430
1431         read_alternate_refs(path.buf, cb->fn, cb->data);
1432
1433 out:
1434         strbuf_release(&path);
1435         return 0;
1436 }
1437
1438 void for_each_alternate_ref(alternate_ref_fn fn, void *data)
1439 {
1440         struct alternate_refs_data cb;
1441         cb.fn = fn;
1442         cb.data = data;
1443         foreach_alt_odb(refs_from_alternate_cb, &cb);
1444 }