git-submodule summary: code framework
[git] / transport.c
1 #include "cache.h"
2 #include "transport.h"
3 #include "run-command.h"
4 #ifndef NO_CURL
5 #include "http.h"
6 #endif
7 #include "pkt-line.h"
8 #include "fetch-pack.h"
9 #include "send-pack.h"
10 #include "walker.h"
11 #include "bundle.h"
12 #include "dir.h"
13 #include "refs.h"
14
15 /* rsync support */
16
17 /*
18  * We copy packed-refs and refs/ into a temporary file, then read the
19  * loose refs recursively (sorting whenever possible), and then inserting
20  * those packed refs that are not yet in the list (not validating, but
21  * assuming that the file is sorted).
22  *
23  * Appears refactoring this from refs.c is too cumbersome.
24  */
25
26 static int str_cmp(const void *a, const void *b)
27 {
28         const char *s1 = a;
29         const char *s2 = b;
30
31         return strcmp(s1, s2);
32 }
33
34 /* path->buf + name_offset is expected to point to "refs/" */
35
36 static int read_loose_refs(struct strbuf *path, int name_offset,
37                 struct ref **tail)
38 {
39         DIR *dir = opendir(path->buf);
40         struct dirent *de;
41         struct {
42                 char **entries;
43                 int nr, alloc;
44         } list;
45         int i, pathlen;
46
47         if (!dir)
48                 return -1;
49
50         memset (&list, 0, sizeof(list));
51
52         while ((de = readdir(dir))) {
53                 if (de->d_name[0] == '.' && (de->d_name[1] == '\0' ||
54                                 (de->d_name[1] == '.' &&
55                                  de->d_name[2] == '\0')))
56                         continue;
57                 ALLOC_GROW(list.entries, list.nr + 1, list.alloc);
58                 list.entries[list.nr++] = xstrdup(de->d_name);
59         }
60         closedir(dir);
61
62         /* sort the list */
63
64         qsort(list.entries, list.nr, sizeof(char *), str_cmp);
65
66         pathlen = path->len;
67         strbuf_addch(path, '/');
68
69         for (i = 0; i < list.nr; i++, strbuf_setlen(path, pathlen + 1)) {
70                 strbuf_addstr(path, list.entries[i]);
71                 if (read_loose_refs(path, name_offset, tail)) {
72                         int fd = open(path->buf, O_RDONLY);
73                         char buffer[40];
74                         struct ref *next;
75
76                         if (fd < 0)
77                                 continue;
78                         next = alloc_ref(path->len - name_offset + 1);
79                         if (read_in_full(fd, buffer, 40) != 40 ||
80                                         get_sha1_hex(buffer, next->old_sha1)) {
81                                 close(fd);
82                                 free(next);
83                                 continue;
84                         }
85                         close(fd);
86                         strcpy(next->name, path->buf + name_offset);
87                         (*tail)->next = next;
88                         *tail = next;
89                 }
90         }
91         strbuf_setlen(path, pathlen);
92
93         for (i = 0; i < list.nr; i++)
94                 free(list.entries[i]);
95         free(list.entries);
96
97         return 0;
98 }
99
100 /* insert the packed refs for which no loose refs were found */
101
102 static void insert_packed_refs(const char *packed_refs, struct ref **list)
103 {
104         FILE *f = fopen(packed_refs, "r");
105         static char buffer[PATH_MAX];
106
107         if (!f)
108                 return;
109
110         for (;;) {
111                 int cmp = cmp, len;
112
113                 if (!fgets(buffer, sizeof(buffer), f)) {
114                         fclose(f);
115                         return;
116                 }
117
118                 if (hexval(buffer[0]) > 0xf)
119                         continue;
120                 len = strlen(buffer);
121                 if (len && buffer[len - 1] == '\n')
122                         buffer[--len] = '\0';
123                 if (len < 41)
124                         continue;
125                 while ((*list)->next &&
126                                 (cmp = strcmp(buffer + 41,
127                                       (*list)->next->name)) > 0)
128                         list = &(*list)->next;
129                 if (!(*list)->next || cmp < 0) {
130                         struct ref *next = alloc_ref(len - 40);
131                         buffer[40] = '\0';
132                         if (get_sha1_hex(buffer, next->old_sha1)) {
133                                 warning ("invalid SHA-1: %s", buffer);
134                                 free(next);
135                                 continue;
136                         }
137                         strcpy(next->name, buffer + 41);
138                         next->next = (*list)->next;
139                         (*list)->next = next;
140                         list = &(*list)->next;
141                 }
142         }
143 }
144
145 static struct ref *get_refs_via_rsync(struct transport *transport)
146 {
147         struct strbuf buf = STRBUF_INIT, temp_dir = STRBUF_INIT;
148         struct ref dummy, *tail = &dummy;
149         struct child_process rsync;
150         const char *args[5];
151         int temp_dir_len;
152
153         /* copy the refs to the temporary directory */
154
155         strbuf_addstr(&temp_dir, git_path("rsync-refs-XXXXXX"));
156         if (!mkdtemp(temp_dir.buf))
157                 die ("Could not make temporary directory");
158         temp_dir_len = temp_dir.len;
159
160         strbuf_addstr(&buf, transport->url);
161         strbuf_addstr(&buf, "/refs");
162
163         memset(&rsync, 0, sizeof(rsync));
164         rsync.argv = args;
165         rsync.stdout_to_stderr = 1;
166         args[0] = "rsync";
167         args[1] = (transport->verbose > 0) ? "-rv" : "-r";
168         args[2] = buf.buf;
169         args[3] = temp_dir.buf;
170         args[4] = NULL;
171
172         if (run_command(&rsync))
173                 die ("Could not run rsync to get refs");
174
175         strbuf_reset(&buf);
176         strbuf_addstr(&buf, transport->url);
177         strbuf_addstr(&buf, "/packed-refs");
178
179         args[2] = buf.buf;
180
181         if (run_command(&rsync))
182                 die ("Could not run rsync to get refs");
183
184         /* read the copied refs */
185
186         strbuf_addstr(&temp_dir, "/refs");
187         read_loose_refs(&temp_dir, temp_dir_len + 1, &tail);
188         strbuf_setlen(&temp_dir, temp_dir_len);
189
190         tail = &dummy;
191         strbuf_addstr(&temp_dir, "/packed-refs");
192         insert_packed_refs(temp_dir.buf, &tail);
193         strbuf_setlen(&temp_dir, temp_dir_len);
194
195         if (remove_dir_recursively(&temp_dir, 0))
196                 warning ("Error removing temporary directory %s.",
197                                 temp_dir.buf);
198
199         strbuf_release(&buf);
200         strbuf_release(&temp_dir);
201
202         return dummy.next;
203 }
204
205 static int fetch_objs_via_rsync(struct transport *transport,
206                                  int nr_objs, struct ref **to_fetch)
207 {
208         struct strbuf buf = STRBUF_INIT;
209         struct child_process rsync;
210         const char *args[8];
211         int result;
212
213         strbuf_addstr(&buf, transport->url);
214         strbuf_addstr(&buf, "/objects/");
215
216         memset(&rsync, 0, sizeof(rsync));
217         rsync.argv = args;
218         rsync.stdout_to_stderr = 1;
219         args[0] = "rsync";
220         args[1] = (transport->verbose > 0) ? "-rv" : "-r";
221         args[2] = "--ignore-existing";
222         args[3] = "--exclude";
223         args[4] = "info";
224         args[5] = buf.buf;
225         args[6] = get_object_directory();
226         args[7] = NULL;
227
228         /* NEEDSWORK: handle one level of alternates */
229         result = run_command(&rsync);
230
231         strbuf_release(&buf);
232
233         return result;
234 }
235
236 static int write_one_ref(const char *name, const unsigned char *sha1,
237                 int flags, void *data)
238 {
239         struct strbuf *buf = data;
240         int len = buf->len;
241         FILE *f;
242
243         /* when called via for_each_ref(), flags is non-zero */
244         if (flags && prefixcmp(name, "refs/heads/") &&
245                         prefixcmp(name, "refs/tags/"))
246                 return 0;
247
248         strbuf_addstr(buf, name);
249         if (safe_create_leading_directories(buf->buf) ||
250                         !(f = fopen(buf->buf, "w")) ||
251                         fprintf(f, "%s\n", sha1_to_hex(sha1)) < 0 ||
252                         fclose(f))
253                 return error("problems writing temporary file %s", buf->buf);
254         strbuf_setlen(buf, len);
255         return 0;
256 }
257
258 static int write_refs_to_temp_dir(struct strbuf *temp_dir,
259                 int refspec_nr, const char **refspec)
260 {
261         int i;
262
263         for (i = 0; i < refspec_nr; i++) {
264                 unsigned char sha1[20];
265                 char *ref;
266
267                 if (dwim_ref(refspec[i], strlen(refspec[i]), sha1, &ref) != 1)
268                         return error("Could not get ref %s", refspec[i]);
269
270                 if (write_one_ref(ref, sha1, 0, temp_dir)) {
271                         free(ref);
272                         return -1;
273                 }
274                 free(ref);
275         }
276         return 0;
277 }
278
279 static int rsync_transport_push(struct transport *transport,
280                 int refspec_nr, const char **refspec, int flags)
281 {
282         struct strbuf buf = STRBUF_INIT, temp_dir = STRBUF_INIT;
283         int result = 0, i;
284         struct child_process rsync;
285         const char *args[10];
286
287         if (flags & TRANSPORT_PUSH_MIRROR)
288                 return error("rsync transport does not support mirror mode");
289
290         /* first push the objects */
291
292         strbuf_addstr(&buf, transport->url);
293         strbuf_addch(&buf, '/');
294
295         memset(&rsync, 0, sizeof(rsync));
296         rsync.argv = args;
297         rsync.stdout_to_stderr = 1;
298         i = 0;
299         args[i++] = "rsync";
300         args[i++] = "-a";
301         if (flags & TRANSPORT_PUSH_DRY_RUN)
302                 args[i++] = "--dry-run";
303         if (transport->verbose > 0)
304                 args[i++] = "-v";
305         args[i++] = "--ignore-existing";
306         args[i++] = "--exclude";
307         args[i++] = "info";
308         args[i++] = get_object_directory();
309         args[i++] = buf.buf;
310         args[i++] = NULL;
311
312         if (run_command(&rsync))
313                 return error("Could not push objects to %s", transport->url);
314
315         /* copy the refs to the temporary directory; they could be packed. */
316
317         strbuf_addstr(&temp_dir, git_path("rsync-refs-XXXXXX"));
318         if (!mkdtemp(temp_dir.buf))
319                 die ("Could not make temporary directory");
320         strbuf_addch(&temp_dir, '/');
321
322         if (flags & TRANSPORT_PUSH_ALL) {
323                 if (for_each_ref(write_one_ref, &temp_dir))
324                         return -1;
325         } else if (write_refs_to_temp_dir(&temp_dir, refspec_nr, refspec))
326                 return -1;
327
328         i = 2;
329         if (flags & TRANSPORT_PUSH_DRY_RUN)
330                 args[i++] = "--dry-run";
331         if (!(flags & TRANSPORT_PUSH_FORCE))
332                 args[i++] = "--ignore-existing";
333         args[i++] = temp_dir.buf;
334         args[i++] = transport->url;
335         args[i++] = NULL;
336         if (run_command(&rsync))
337                 result = error("Could not push to %s", transport->url);
338
339         if (remove_dir_recursively(&temp_dir, 0))
340                 warning ("Could not remove temporary directory %s.",
341                                 temp_dir.buf);
342
343         strbuf_release(&buf);
344         strbuf_release(&temp_dir);
345
346         return result;
347 }
348
349 /* Generic functions for using commit walkers */
350
351 #ifndef NO_CURL /* http fetch is the only user */
352 static int fetch_objs_via_walker(struct transport *transport,
353                                  int nr_objs, struct ref **to_fetch)
354 {
355         char *dest = xstrdup(transport->url);
356         struct walker *walker = transport->data;
357         char **objs = xmalloc(nr_objs * sizeof(*objs));
358         int i;
359
360         walker->get_all = 1;
361         walker->get_tree = 1;
362         walker->get_history = 1;
363         walker->get_verbosely = transport->verbose >= 0;
364         walker->get_recover = 0;
365
366         for (i = 0; i < nr_objs; i++)
367                 objs[i] = xstrdup(sha1_to_hex(to_fetch[i]->old_sha1));
368
369         if (walker_fetch(walker, nr_objs, objs, NULL, NULL))
370                 die("Fetch failed.");
371
372         for (i = 0; i < nr_objs; i++)
373                 free(objs[i]);
374         free(objs);
375         free(dest);
376         return 0;
377 }
378 #endif /* NO_CURL */
379
380 static int disconnect_walker(struct transport *transport)
381 {
382         struct walker *walker = transport->data;
383         if (walker)
384                 walker_free(walker);
385         return 0;
386 }
387
388 #ifndef NO_CURL
389 static int curl_transport_push(struct transport *transport, int refspec_nr, const char **refspec, int flags)
390 {
391         const char **argv;
392         int argc;
393         int err;
394
395         if (flags & TRANSPORT_PUSH_MIRROR)
396                 return error("http transport does not support mirror mode");
397
398         argv = xmalloc((refspec_nr + 12) * sizeof(char *));
399         argv[0] = "http-push";
400         argc = 1;
401         if (flags & TRANSPORT_PUSH_ALL)
402                 argv[argc++] = "--all";
403         if (flags & TRANSPORT_PUSH_FORCE)
404                 argv[argc++] = "--force";
405         if (flags & TRANSPORT_PUSH_DRY_RUN)
406                 argv[argc++] = "--dry-run";
407         if (flags & TRANSPORT_PUSH_VERBOSE)
408                 argv[argc++] = "--verbose";
409         argv[argc++] = transport->url;
410         while (refspec_nr--)
411                 argv[argc++] = *refspec++;
412         argv[argc] = NULL;
413         err = run_command_v_opt(argv, RUN_GIT_CMD);
414         switch (err) {
415         case -ERR_RUN_COMMAND_FORK:
416                 error("unable to fork for %s", argv[0]);
417         case -ERR_RUN_COMMAND_EXEC:
418                 error("unable to exec %s", argv[0]);
419                 break;
420         case -ERR_RUN_COMMAND_WAITPID:
421         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
422         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
423         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
424                 error("%s died with strange error", argv[0]);
425         }
426         return !!err;
427 }
428
429 static struct ref *get_refs_via_curl(struct transport *transport)
430 {
431         struct strbuf buffer = STRBUF_INIT;
432         char *data, *start, *mid;
433         char *ref_name;
434         char *refs_url;
435         int i = 0;
436
437         struct active_request_slot *slot;
438         struct slot_results results;
439
440         struct ref *refs = NULL;
441         struct ref *ref = NULL;
442         struct ref *last_ref = NULL;
443
444         if (!transport->data)
445                 transport->data = get_http_walker(transport->url,
446                                                 transport->remote);
447
448         refs_url = xmalloc(strlen(transport->url) + 11);
449         sprintf(refs_url, "%s/info/refs", transport->url);
450
451         slot = get_active_slot();
452         slot->results = &results;
453         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
454         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
455         curl_easy_setopt(slot->curl, CURLOPT_URL, refs_url);
456         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
457
458         if (start_active_slot(slot)) {
459                 run_active_slot(slot);
460                 if (results.curl_result != CURLE_OK) {
461                         strbuf_release(&buffer);
462                         if (missing_target(&results)) {
463                                 return NULL;
464                         } else {
465                                 error("%s", curl_errorstr);
466                                 return NULL;
467                         }
468                 }
469         } else {
470                 strbuf_release(&buffer);
471                 error("Unable to start request");
472                 return NULL;
473         }
474
475         data = buffer.buf;
476         start = NULL;
477         mid = data;
478         while (i < buffer.len) {
479                 if (!start)
480                         start = &data[i];
481                 if (data[i] == '\t')
482                         mid = &data[i];
483                 if (data[i] == '\n') {
484                         data[i] = 0;
485                         ref_name = mid + 1;
486                         ref = xmalloc(sizeof(struct ref) +
487                                       strlen(ref_name) + 1);
488                         memset(ref, 0, sizeof(struct ref));
489                         strcpy(ref->name, ref_name);
490                         get_sha1_hex(start, ref->old_sha1);
491                         if (!refs)
492                                 refs = ref;
493                         if (last_ref)
494                                 last_ref->next = ref;
495                         last_ref = ref;
496                         start = NULL;
497                 }
498                 i++;
499         }
500
501         strbuf_release(&buffer);
502
503         return refs;
504 }
505
506 static int fetch_objs_via_curl(struct transport *transport,
507                                  int nr_objs, struct ref **to_fetch)
508 {
509         if (!transport->data)
510                 transport->data = get_http_walker(transport->url,
511                                                 transport->remote);
512         return fetch_objs_via_walker(transport, nr_objs, to_fetch);
513 }
514
515 #endif
516
517 struct bundle_transport_data {
518         int fd;
519         struct bundle_header header;
520 };
521
522 static struct ref *get_refs_from_bundle(struct transport *transport)
523 {
524         struct bundle_transport_data *data = transport->data;
525         struct ref *result = NULL;
526         int i;
527
528         if (data->fd > 0)
529                 close(data->fd);
530         data->fd = read_bundle_header(transport->url, &data->header);
531         if (data->fd < 0)
532                 die ("Could not read bundle '%s'.", transport->url);
533         for (i = 0; i < data->header.references.nr; i++) {
534                 struct ref_list_entry *e = data->header.references.list + i;
535                 struct ref *ref = alloc_ref(strlen(e->name) + 1);
536                 hashcpy(ref->old_sha1, e->sha1);
537                 strcpy(ref->name, e->name);
538                 ref->next = result;
539                 result = ref;
540         }
541         return result;
542 }
543
544 static int fetch_refs_from_bundle(struct transport *transport,
545                                int nr_heads, struct ref **to_fetch)
546 {
547         struct bundle_transport_data *data = transport->data;
548         return unbundle(&data->header, data->fd);
549 }
550
551 static int close_bundle(struct transport *transport)
552 {
553         struct bundle_transport_data *data = transport->data;
554         if (data->fd > 0)
555                 close(data->fd);
556         free(data);
557         return 0;
558 }
559
560 struct git_transport_data {
561         unsigned thin : 1;
562         unsigned keep : 1;
563         int depth;
564         struct child_process *conn;
565         int fd[2];
566         const char *uploadpack;
567         const char *receivepack;
568 };
569
570 static int set_git_option(struct transport *connection,
571                           const char *name, const char *value)
572 {
573         struct git_transport_data *data = connection->data;
574         if (!strcmp(name, TRANS_OPT_UPLOADPACK)) {
575                 data->uploadpack = value;
576                 return 0;
577         } else if (!strcmp(name, TRANS_OPT_RECEIVEPACK)) {
578                 data->receivepack = value;
579                 return 0;
580         } else if (!strcmp(name, TRANS_OPT_THIN)) {
581                 data->thin = !!value;
582                 return 0;
583         } else if (!strcmp(name, TRANS_OPT_KEEP)) {
584                 data->keep = !!value;
585                 return 0;
586         } else if (!strcmp(name, TRANS_OPT_DEPTH)) {
587                 if (!value)
588                         data->depth = 0;
589                 else
590                         data->depth = atoi(value);
591                 return 0;
592         }
593         return 1;
594 }
595
596 static int connect_setup(struct transport *transport)
597 {
598         struct git_transport_data *data = transport->data;
599         data->conn = git_connect(data->fd, transport->url, data->uploadpack, 0);
600         return 0;
601 }
602
603 static struct ref *get_refs_via_connect(struct transport *transport)
604 {
605         struct git_transport_data *data = transport->data;
606         struct ref *refs;
607
608         connect_setup(transport);
609         get_remote_heads(data->fd[0], &refs, 0, NULL, 0);
610
611         return refs;
612 }
613
614 static int fetch_refs_via_pack(struct transport *transport,
615                                int nr_heads, struct ref **to_fetch)
616 {
617         struct git_transport_data *data = transport->data;
618         char **heads = xmalloc(nr_heads * sizeof(*heads));
619         char **origh = xmalloc(nr_heads * sizeof(*origh));
620         const struct ref *refs;
621         char *dest = xstrdup(transport->url);
622         struct fetch_pack_args args;
623         int i;
624         struct ref *refs_tmp = NULL;
625
626         memset(&args, 0, sizeof(args));
627         args.uploadpack = data->uploadpack;
628         args.keep_pack = data->keep;
629         args.lock_pack = 1;
630         args.use_thin_pack = data->thin;
631         args.verbose = transport->verbose > 0;
632         args.depth = data->depth;
633
634         for (i = 0; i < nr_heads; i++)
635                 origh[i] = heads[i] = xstrdup(to_fetch[i]->name);
636
637         if (!data->conn) {
638                 connect_setup(transport);
639                 get_remote_heads(data->fd[0], &refs_tmp, 0, NULL, 0);
640         }
641
642         refs = fetch_pack(&args, data->fd, data->conn,
643                           refs_tmp ? refs_tmp : transport->remote_refs,
644                           dest, nr_heads, heads, &transport->pack_lockfile);
645         close(data->fd[0]);
646         close(data->fd[1]);
647         if (finish_connect(data->conn))
648                 refs = NULL;
649         data->conn = NULL;
650
651         free_refs(refs_tmp);
652
653         for (i = 0; i < nr_heads; i++)
654                 free(origh[i]);
655         free(origh);
656         free(heads);
657         free(dest);
658         return (refs ? 0 : -1);
659 }
660
661 static int git_transport_push(struct transport *transport, int refspec_nr, const char **refspec, int flags)
662 {
663         struct git_transport_data *data = transport->data;
664         struct send_pack_args args;
665
666         args.receivepack = data->receivepack;
667         args.send_all = !!(flags & TRANSPORT_PUSH_ALL);
668         args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
669         args.force_update = !!(flags & TRANSPORT_PUSH_FORCE);
670         args.use_thin_pack = data->thin;
671         args.verbose = !!(flags & TRANSPORT_PUSH_VERBOSE);
672         args.dry_run = !!(flags & TRANSPORT_PUSH_DRY_RUN);
673
674         return send_pack(&args, transport->url, transport->remote, refspec_nr, refspec);
675 }
676
677 static int disconnect_git(struct transport *transport)
678 {
679         struct git_transport_data *data = transport->data;
680         if (data->conn) {
681                 packet_flush(data->fd[1]);
682                 close(data->fd[0]);
683                 close(data->fd[1]);
684                 finish_connect(data->conn);
685         }
686
687         free(data);
688         return 0;
689 }
690
691 static int is_local(const char *url)
692 {
693         const char *colon = strchr(url, ':');
694         const char *slash = strchr(url, '/');
695         return !colon || (slash && slash < colon);
696 }
697
698 static int is_file(const char *url)
699 {
700         struct stat buf;
701         if (stat(url, &buf))
702                 return 0;
703         return S_ISREG(buf.st_mode);
704 }
705
706 struct transport *transport_get(struct remote *remote, const char *url)
707 {
708         struct transport *ret = xcalloc(1, sizeof(*ret));
709
710         ret->remote = remote;
711         ret->url = url;
712
713         if (!prefixcmp(url, "rsync://")) {
714                 ret->get_refs_list = get_refs_via_rsync;
715                 ret->fetch = fetch_objs_via_rsync;
716                 ret->push = rsync_transport_push;
717
718         } else if (!prefixcmp(url, "http://")
719                 || !prefixcmp(url, "https://")
720                 || !prefixcmp(url, "ftp://")) {
721 #ifdef NO_CURL
722                 error("git was compiled without libcurl support.");
723 #else
724                 ret->get_refs_list = get_refs_via_curl;
725                 ret->fetch = fetch_objs_via_curl;
726                 ret->push = curl_transport_push;
727 #endif
728                 ret->disconnect = disconnect_walker;
729
730         } else if (is_local(url) && is_file(url)) {
731                 struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
732                 ret->data = data;
733                 ret->get_refs_list = get_refs_from_bundle;
734                 ret->fetch = fetch_refs_from_bundle;
735                 ret->disconnect = close_bundle;
736
737         } else {
738                 struct git_transport_data *data = xcalloc(1, sizeof(*data));
739                 ret->data = data;
740                 ret->set_option = set_git_option;
741                 ret->get_refs_list = get_refs_via_connect;
742                 ret->fetch = fetch_refs_via_pack;
743                 ret->push = git_transport_push;
744                 ret->disconnect = disconnect_git;
745
746                 data->thin = 1;
747                 data->conn = NULL;
748                 data->uploadpack = "git-upload-pack";
749                 if (remote && remote->uploadpack)
750                         data->uploadpack = remote->uploadpack;
751                 data->receivepack = "git-receive-pack";
752                 if (remote && remote->receivepack)
753                         data->receivepack = remote->receivepack;
754         }
755
756         return ret;
757 }
758
759 int transport_set_option(struct transport *transport,
760                          const char *name, const char *value)
761 {
762         if (transport->set_option)
763                 return transport->set_option(transport, name, value);
764         return 1;
765 }
766
767 int transport_push(struct transport *transport,
768                    int refspec_nr, const char **refspec, int flags)
769 {
770         if (!transport->push)
771                 return 1;
772         return transport->push(transport, refspec_nr, refspec, flags);
773 }
774
775 const struct ref *transport_get_remote_refs(struct transport *transport)
776 {
777         if (!transport->remote_refs)
778                 transport->remote_refs = transport->get_refs_list(transport);
779         return transport->remote_refs;
780 }
781
782 int transport_fetch_refs(struct transport *transport, struct ref *refs)
783 {
784         int rc;
785         int nr_heads = 0, nr_alloc = 0;
786         struct ref **heads = NULL;
787         struct ref *rm;
788
789         for (rm = refs; rm; rm = rm->next) {
790                 if (rm->peer_ref &&
791                     !hashcmp(rm->peer_ref->old_sha1, rm->old_sha1))
792                         continue;
793                 ALLOC_GROW(heads, nr_heads + 1, nr_alloc);
794                 heads[nr_heads++] = rm;
795         }
796
797         rc = transport->fetch(transport, nr_heads, heads);
798         free(heads);
799         return rc;
800 }
801
802 void transport_unlock_pack(struct transport *transport)
803 {
804         if (transport->pack_lockfile) {
805                 unlink(transport->pack_lockfile);
806                 free(transport->pack_lockfile);
807                 transport->pack_lockfile = NULL;
808         }
809 }
810
811 int transport_disconnect(struct transport *transport)
812 {
813         int ret = 0;
814         if (transport->disconnect)
815                 ret = transport->disconnect(transport);
816         free(transport);
817         return ret;
818 }