upload-pack: split check_unreachable() in two, prep for get_reachable_list()
[git] / upload-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "sideband.h"
5 #include "tag.h"
6 #include "object.h"
7 #include "commit.h"
8 #include "exec_cmd.h"
9 #include "diff.h"
10 #include "revision.h"
11 #include "list-objects.h"
12 #include "run-command.h"
13 #include "connect.h"
14 #include "sigchain.h"
15 #include "version.h"
16 #include "string-list.h"
17 #include "argv-array.h"
18
19 static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=<n>] <dir>";
20
21 /* Remember to update object flag allocation in object.h */
22 #define THEY_HAVE       (1u << 11)
23 #define OUR_REF         (1u << 12)
24 #define WANTED          (1u << 13)
25 #define COMMON_KNOWN    (1u << 14)
26 #define REACHABLE       (1u << 15)
27
28 #define SHALLOW         (1u << 16)
29 #define NOT_SHALLOW     (1u << 17)
30 #define CLIENT_SHALLOW  (1u << 18)
31 #define HIDDEN_REF      (1u << 19)
32
33 static unsigned long oldest_have;
34
35 static int multi_ack;
36 static int no_done;
37 static int use_thin_pack, use_ofs_delta, use_include_tag;
38 static int no_progress, daemon_mode;
39 /* Allow specifying sha1 if it is a ref tip. */
40 #define ALLOW_TIP_SHA1  01
41 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
42 #define ALLOW_REACHABLE_SHA1    02
43 static unsigned int allow_unadvertised_object_request;
44 static int shallow_nr;
45 static struct object_array have_obj;
46 static struct object_array want_obj;
47 static struct object_array extra_edge_obj;
48 static unsigned int timeout;
49 static int keepalive = 5;
50 /* 0 for no sideband,
51  * otherwise maximum packet size (up to 65520 bytes).
52  */
53 static int use_sideband;
54 static int advertise_refs;
55 static int stateless_rpc;
56
57 static void reset_timeout(void)
58 {
59         alarm(timeout);
60 }
61
62 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
63 {
64         if (use_sideband)
65                 return send_sideband(1, fd, data, sz, use_sideband);
66         if (fd == 3)
67                 /* emergency quit */
68                 fd = 2;
69         if (fd == 2) {
70                 /* XXX: are we happy to lose stuff here? */
71                 xwrite(fd, data, sz);
72                 return sz;
73         }
74         write_or_die(fd, data, sz);
75         return sz;
76 }
77
78 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
79 {
80         FILE *fp = cb_data;
81         if (graft->nr_parent == -1)
82                 fprintf(fp, "--shallow %s\n", oid_to_hex(&graft->oid));
83         return 0;
84 }
85
86 static void create_pack_file(void)
87 {
88         struct child_process pack_objects = CHILD_PROCESS_INIT;
89         char data[8193], progress[128];
90         char abort_msg[] = "aborting due to possible repository "
91                 "corruption on the remote side.";
92         int buffered = -1;
93         ssize_t sz;
94         const char *argv[13];
95         int i, arg = 0;
96         FILE *pipe_fd;
97
98         if (shallow_nr) {
99                 argv[arg++] = "--shallow-file";
100                 argv[arg++] = "";
101         }
102         argv[arg++] = "pack-objects";
103         argv[arg++] = "--revs";
104         if (use_thin_pack)
105                 argv[arg++] = "--thin";
106
107         argv[arg++] = "--stdout";
108         if (shallow_nr)
109                 argv[arg++] = "--shallow";
110         if (!no_progress)
111                 argv[arg++] = "--progress";
112         if (use_ofs_delta)
113                 argv[arg++] = "--delta-base-offset";
114         if (use_include_tag)
115                 argv[arg++] = "--include-tag";
116         argv[arg++] = NULL;
117
118         pack_objects.in = -1;
119         pack_objects.out = -1;
120         pack_objects.err = -1;
121         pack_objects.git_cmd = 1;
122         pack_objects.argv = argv;
123
124         if (start_command(&pack_objects))
125                 die("git upload-pack: unable to fork git-pack-objects");
126
127         pipe_fd = xfdopen(pack_objects.in, "w");
128
129         if (shallow_nr)
130                 for_each_commit_graft(write_one_shallow, pipe_fd);
131
132         for (i = 0; i < want_obj.nr; i++)
133                 fprintf(pipe_fd, "%s\n",
134                         oid_to_hex(&want_obj.objects[i].item->oid));
135         fprintf(pipe_fd, "--not\n");
136         for (i = 0; i < have_obj.nr; i++)
137                 fprintf(pipe_fd, "%s\n",
138                         oid_to_hex(&have_obj.objects[i].item->oid));
139         for (i = 0; i < extra_edge_obj.nr; i++)
140                 fprintf(pipe_fd, "%s\n",
141                         oid_to_hex(&extra_edge_obj.objects[i].item->oid));
142         fprintf(pipe_fd, "\n");
143         fflush(pipe_fd);
144         fclose(pipe_fd);
145
146         /* We read from pack_objects.err to capture stderr output for
147          * progress bar, and pack_objects.out to capture the pack data.
148          */
149
150         while (1) {
151                 struct pollfd pfd[2];
152                 int pe, pu, pollsize;
153                 int ret;
154
155                 reset_timeout();
156
157                 pollsize = 0;
158                 pe = pu = -1;
159
160                 if (0 <= pack_objects.out) {
161                         pfd[pollsize].fd = pack_objects.out;
162                         pfd[pollsize].events = POLLIN;
163                         pu = pollsize;
164                         pollsize++;
165                 }
166                 if (0 <= pack_objects.err) {
167                         pfd[pollsize].fd = pack_objects.err;
168                         pfd[pollsize].events = POLLIN;
169                         pe = pollsize;
170                         pollsize++;
171                 }
172
173                 if (!pollsize)
174                         break;
175
176                 ret = poll(pfd, pollsize,
177                         keepalive < 0 ? -1 : 1000 * keepalive);
178
179                 if (ret < 0) {
180                         if (errno != EINTR) {
181                                 error("poll failed, resuming: %s",
182                                       strerror(errno));
183                                 sleep(1);
184                         }
185                         continue;
186                 }
187                 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
188                         /* Status ready; we ship that in the side-band
189                          * or dump to the standard error.
190                          */
191                         sz = xread(pack_objects.err, progress,
192                                   sizeof(progress));
193                         if (0 < sz)
194                                 send_client_data(2, progress, sz);
195                         else if (sz == 0) {
196                                 close(pack_objects.err);
197                                 pack_objects.err = -1;
198                         }
199                         else
200                                 goto fail;
201                         /* give priority to status messages */
202                         continue;
203                 }
204                 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
205                         /* Data ready; we keep the last byte to ourselves
206                          * in case we detect broken rev-list, so that we
207                          * can leave the stream corrupted.  This is
208                          * unfortunate -- unpack-objects would happily
209                          * accept a valid packdata with trailing garbage,
210                          * so appending garbage after we pass all the
211                          * pack data is not good enough to signal
212                          * breakage to downstream.
213                          */
214                         char *cp = data;
215                         ssize_t outsz = 0;
216                         if (0 <= buffered) {
217                                 *cp++ = buffered;
218                                 outsz++;
219                         }
220                         sz = xread(pack_objects.out, cp,
221                                   sizeof(data) - outsz);
222                         if (0 < sz)
223                                 ;
224                         else if (sz == 0) {
225                                 close(pack_objects.out);
226                                 pack_objects.out = -1;
227                         }
228                         else
229                                 goto fail;
230                         sz += outsz;
231                         if (1 < sz) {
232                                 buffered = data[sz-1] & 0xFF;
233                                 sz--;
234                         }
235                         else
236                                 buffered = -1;
237                         sz = send_client_data(1, data, sz);
238                         if (sz < 0)
239                                 goto fail;
240                 }
241
242                 /*
243                  * We hit the keepalive timeout without saying anything; send
244                  * an empty message on the data sideband just to let the other
245                  * side know we're still working on it, but don't have any data
246                  * yet.
247                  *
248                  * If we don't have a sideband channel, there's no room in the
249                  * protocol to say anything, so those clients are just out of
250                  * luck.
251                  */
252                 if (!ret && use_sideband) {
253                         static const char buf[] = "0005\1";
254                         write_or_die(1, buf, 5);
255                 }
256         }
257
258         if (finish_command(&pack_objects)) {
259                 error("git upload-pack: git-pack-objects died with error.");
260                 goto fail;
261         }
262
263         /* flush the data */
264         if (0 <= buffered) {
265                 data[0] = buffered;
266                 sz = send_client_data(1, data, 1);
267                 if (sz < 0)
268                         goto fail;
269                 fprintf(stderr, "flushed.\n");
270         }
271         if (use_sideband)
272                 packet_flush(1);
273         return;
274
275  fail:
276         send_client_data(3, abort_msg, sizeof(abort_msg));
277         die("git upload-pack: %s", abort_msg);
278 }
279
280 static int got_sha1(const char *hex, unsigned char *sha1)
281 {
282         struct object *o;
283         int we_knew_they_have = 0;
284
285         if (get_sha1_hex(hex, sha1))
286                 die("git upload-pack: expected SHA1 object, got '%s'", hex);
287         if (!has_sha1_file(sha1))
288                 return -1;
289
290         o = parse_object(sha1);
291         if (!o)
292                 die("oops (%s)", sha1_to_hex(sha1));
293         if (o->type == OBJ_COMMIT) {
294                 struct commit_list *parents;
295                 struct commit *commit = (struct commit *)o;
296                 if (o->flags & THEY_HAVE)
297                         we_knew_they_have = 1;
298                 else
299                         o->flags |= THEY_HAVE;
300                 if (!oldest_have || (commit->date < oldest_have))
301                         oldest_have = commit->date;
302                 for (parents = commit->parents;
303                      parents;
304                      parents = parents->next)
305                         parents->item->object.flags |= THEY_HAVE;
306         }
307         if (!we_knew_they_have) {
308                 add_object_array(o, NULL, &have_obj);
309                 return 1;
310         }
311         return 0;
312 }
313
314 static int reachable(struct commit *want)
315 {
316         struct commit_list *work = NULL;
317
318         commit_list_insert_by_date(want, &work);
319         while (work) {
320                 struct commit_list *list;
321                 struct commit *commit = pop_commit(&work);
322
323                 if (commit->object.flags & THEY_HAVE) {
324                         want->object.flags |= COMMON_KNOWN;
325                         break;
326                 }
327                 if (!commit->object.parsed)
328                         parse_object(commit->object.oid.hash);
329                 if (commit->object.flags & REACHABLE)
330                         continue;
331                 commit->object.flags |= REACHABLE;
332                 if (commit->date < oldest_have)
333                         continue;
334                 for (list = commit->parents; list; list = list->next) {
335                         struct commit *parent = list->item;
336                         if (!(parent->object.flags & REACHABLE))
337                                 commit_list_insert_by_date(parent, &work);
338                 }
339         }
340         want->object.flags |= REACHABLE;
341         clear_commit_marks(want, REACHABLE);
342         free_commit_list(work);
343         return (want->object.flags & COMMON_KNOWN);
344 }
345
346 static int ok_to_give_up(void)
347 {
348         int i;
349
350         if (!have_obj.nr)
351                 return 0;
352
353         for (i = 0; i < want_obj.nr; i++) {
354                 struct object *want = want_obj.objects[i].item;
355
356                 if (want->flags & COMMON_KNOWN)
357                         continue;
358                 want = deref_tag(want, "a want line", 0);
359                 if (!want || want->type != OBJ_COMMIT) {
360                         /* no way to tell if this is reachable by
361                          * looking at the ancestry chain alone, so
362                          * leave a note to ourselves not to worry about
363                          * this object anymore.
364                          */
365                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
366                         continue;
367                 }
368                 if (!reachable((struct commit *)want))
369                         return 0;
370         }
371         return 1;
372 }
373
374 static int get_common_commits(void)
375 {
376         unsigned char sha1[20];
377         char last_hex[41];
378         int got_common = 0;
379         int got_other = 0;
380         int sent_ready = 0;
381
382         save_commit_buffer = 0;
383
384         for (;;) {
385                 char *line = packet_read_line(0, NULL);
386                 const char *arg;
387
388                 reset_timeout();
389
390                 if (!line) {
391                         if (multi_ack == 2 && got_common
392                             && !got_other && ok_to_give_up()) {
393                                 sent_ready = 1;
394                                 packet_write(1, "ACK %s ready\n", last_hex);
395                         }
396                         if (have_obj.nr == 0 || multi_ack)
397                                 packet_write(1, "NAK\n");
398
399                         if (no_done && sent_ready) {
400                                 packet_write(1, "ACK %s\n", last_hex);
401                                 return 0;
402                         }
403                         if (stateless_rpc)
404                                 exit(0);
405                         got_common = 0;
406                         got_other = 0;
407                         continue;
408                 }
409                 if (skip_prefix(line, "have ", &arg)) {
410                         switch (got_sha1(arg, sha1)) {
411                         case -1: /* they have what we do not */
412                                 got_other = 1;
413                                 if (multi_ack && ok_to_give_up()) {
414                                         const char *hex = sha1_to_hex(sha1);
415                                         if (multi_ack == 2) {
416                                                 sent_ready = 1;
417                                                 packet_write(1, "ACK %s ready\n", hex);
418                                         } else
419                                                 packet_write(1, "ACK %s continue\n", hex);
420                                 }
421                                 break;
422                         default:
423                                 got_common = 1;
424                                 memcpy(last_hex, sha1_to_hex(sha1), 41);
425                                 if (multi_ack == 2)
426                                         packet_write(1, "ACK %s common\n", last_hex);
427                                 else if (multi_ack)
428                                         packet_write(1, "ACK %s continue\n", last_hex);
429                                 else if (have_obj.nr == 1)
430                                         packet_write(1, "ACK %s\n", last_hex);
431                                 break;
432                         }
433                         continue;
434                 }
435                 if (!strcmp(line, "done")) {
436                         if (have_obj.nr > 0) {
437                                 if (multi_ack)
438                                         packet_write(1, "ACK %s\n", last_hex);
439                                 return 0;
440                         }
441                         packet_write(1, "NAK\n");
442                         return -1;
443                 }
444                 die("git upload-pack: expected SHA1 list, got '%s'", line);
445         }
446 }
447
448 static int is_our_ref(struct object *o)
449 {
450         int allow_hidden_ref = (allow_unadvertised_object_request &
451                         (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
452         return o->flags & ((allow_hidden_ref ? HIDDEN_REF : 0) | OUR_REF);
453 }
454
455 /*
456  * on successful case, it's up to the caller to close cmd->out
457  */
458 static int do_reachable_revlist(struct child_process *cmd,
459                                 struct object_array *src)
460 {
461         static const char *argv[] = {
462                 "rev-list", "--stdin", NULL,
463         };
464         struct object *o;
465         char namebuf[42]; /* ^ + SHA-1 + LF */
466         int i;
467
468         cmd->argv = argv;
469         cmd->git_cmd = 1;
470         cmd->no_stderr = 1;
471         cmd->in = -1;
472         cmd->out = -1;
473
474         /*
475          * If the next rev-list --stdin encounters an unknown commit,
476          * it terminates, which will cause SIGPIPE in the write loop
477          * below.
478          */
479         sigchain_push(SIGPIPE, SIG_IGN);
480
481         if (start_command(cmd))
482                 goto error;
483
484         namebuf[0] = '^';
485         namebuf[41] = '\n';
486         for (i = get_max_object_index(); 0 < i; ) {
487                 o = get_indexed_object(--i);
488                 if (!o)
489                         continue;
490                 if (!is_our_ref(o))
491                         continue;
492                 memcpy(namebuf + 1, oid_to_hex(&o->oid), GIT_SHA1_HEXSZ);
493                 if (write_in_full(cmd->in, namebuf, 42) < 0)
494                         goto error;
495         }
496         namebuf[40] = '\n';
497         for (i = 0; i < src->nr; i++) {
498                 o = src->objects[i].item;
499                 if (is_our_ref(o))
500                         continue;
501                 memcpy(namebuf, oid_to_hex(&o->oid), GIT_SHA1_HEXSZ);
502                 if (write_in_full(cmd->in, namebuf, 41) < 0)
503                         goto error;
504         }
505         close(cmd->in);
506         cmd->in = -1;
507         sigchain_pop(SIGPIPE);
508
509         return 0;
510
511 error:
512         sigchain_pop(SIGPIPE);
513
514         if (cmd->in >= 0)
515                 close(cmd->in);
516         if (cmd->out >= 0)
517                 close(cmd->out);
518         return -1;
519 }
520
521 static int has_unreachable(struct object_array *src)
522 {
523         struct child_process cmd = CHILD_PROCESS_INIT;
524         char buf[1];
525         int i;
526
527         if (do_reachable_revlist(&cmd, src) < 0)
528                 return 1;
529
530         /*
531          * The commits out of the rev-list are not ancestors of
532          * our ref.
533          */
534         i = read_in_full(cmd.out, buf, 1);
535         if (i)
536                 goto error;
537         close(cmd.out);
538         cmd.out = -1;
539
540         /*
541          * rev-list may have died by encountering a bad commit
542          * in the history, in which case we do want to bail out
543          * even when it showed no commit.
544          */
545         if (finish_command(&cmd))
546                 goto error;
547
548         /* All the non-tip ones are ancestors of what we advertised */
549         return 0;
550
551 error:
552         sigchain_pop(SIGPIPE);
553         if (cmd.out >= 0)
554                 close(cmd.out);
555         return 1;
556 }
557
558 static void check_non_tip(void)
559 {
560         int i;
561
562         /*
563          * In the normal in-process case without
564          * uploadpack.allowReachableSHA1InWant,
565          * non-tip requests can never happen.
566          */
567         if (!stateless_rpc && !(allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1))
568                 goto error;
569         if (!has_unreachable(&want_obj))
570                 /* All the non-tip ones are ancestors of what we advertised */
571                 return;
572
573 error:
574         /* Pick one of them (we know there at least is one) */
575         for (i = 0; i < want_obj.nr; i++) {
576                 struct object *o = want_obj.objects[i].item;
577                 if (!is_our_ref(o))
578                         die("git upload-pack: not our ref %s",
579                             oid_to_hex(&o->oid));
580         }
581 }
582
583 static void send_shallow(struct commit_list *result)
584 {
585         while (result) {
586                 struct object *object = &result->item->object;
587                 if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
588                         packet_write(1, "shallow %s",
589                                      oid_to_hex(&object->oid));
590                         register_shallow(object->oid.hash);
591                         shallow_nr++;
592                 }
593                 result = result->next;
594         }
595 }
596
597 static void send_unshallow(const struct object_array *shallows)
598 {
599         int i;
600
601         for (i = 0; i < shallows->nr; i++) {
602                 struct object *object = shallows->objects[i].item;
603                 if (object->flags & NOT_SHALLOW) {
604                         struct commit_list *parents;
605                         packet_write(1, "unshallow %s",
606                                      oid_to_hex(&object->oid));
607                         object->flags &= ~CLIENT_SHALLOW;
608                         /*
609                          * We want to _register_ "object" as shallow, but we
610                          * also need to traverse object's parents to deepen a
611                          * shallow clone. Unregister it for now so we can
612                          * parse and add the parents to the want list, then
613                          * re-register it.
614                          */
615                         unregister_shallow(object->oid.hash);
616                         object->parsed = 0;
617                         parse_commit_or_die((struct commit *)object);
618                         parents = ((struct commit *)object)->parents;
619                         while (parents) {
620                                 add_object_array(&parents->item->object,
621                                                  NULL, &want_obj);
622                                 parents = parents->next;
623                         }
624                         add_object_array(object, NULL, &extra_edge_obj);
625                 }
626                 /* make sure commit traversal conforms to client */
627                 register_shallow(object->oid.hash);
628         }
629 }
630
631 static void deepen(int depth, const struct object_array *shallows)
632 {
633         if (depth == INFINITE_DEPTH && !is_repository_shallow()) {
634                 int i;
635
636                 for (i = 0; i < shallows->nr; i++) {
637                         struct object *object = shallows->objects[i].item;
638                         object->flags |= NOT_SHALLOW;
639                 }
640         } else {
641                 struct commit_list *result;
642
643                 result = get_shallow_commits(&want_obj, depth,
644                                              SHALLOW, NOT_SHALLOW);
645                 send_shallow(result);
646                 free_commit_list(result);
647         }
648
649         send_unshallow(shallows);
650         packet_flush(1);
651 }
652
653 static void deepen_by_rev_list(int ac, const char **av,
654                                struct object_array *shallows)
655 {
656         struct commit_list *result;
657
658         result = get_shallow_commits_by_rev_list(ac, av, SHALLOW, NOT_SHALLOW);
659         send_shallow(result);
660         free_commit_list(result);
661         send_unshallow(shallows);
662         packet_flush(1);
663 }
664
665 static void receive_needs(void)
666 {
667         struct object_array shallows = OBJECT_ARRAY_INIT;
668         struct string_list deepen_not = STRING_LIST_INIT_DUP;
669         int depth = 0;
670         int has_non_tip = 0;
671         unsigned long deepen_since = 0;
672         int deepen_rev_list = 0;
673
674         shallow_nr = 0;
675         for (;;) {
676                 struct object *o;
677                 const char *features;
678                 unsigned char sha1_buf[20];
679                 char *line = packet_read_line(0, NULL);
680                 const char *arg;
681
682                 reset_timeout();
683                 if (!line)
684                         break;
685
686                 if (skip_prefix(line, "shallow ", &arg)) {
687                         unsigned char sha1[20];
688                         struct object *object;
689                         if (get_sha1_hex(arg, sha1))
690                                 die("invalid shallow line: %s", line);
691                         object = parse_object(sha1);
692                         if (!object)
693                                 continue;
694                         if (object->type != OBJ_COMMIT)
695                                 die("invalid shallow object %s", sha1_to_hex(sha1));
696                         if (!(object->flags & CLIENT_SHALLOW)) {
697                                 object->flags |= CLIENT_SHALLOW;
698                                 add_object_array(object, NULL, &shallows);
699                         }
700                         continue;
701                 }
702                 if (skip_prefix(line, "deepen ", &arg)) {
703                         char *end = NULL;
704                         depth = strtol(arg, &end, 0);
705                         if (!end || *end || depth <= 0)
706                                 die("Invalid deepen: %s", line);
707                         continue;
708                 }
709                 if (skip_prefix(line, "deepen-since ", &arg)) {
710                         char *end = NULL;
711                         deepen_since = strtoul(arg, &end, 0);
712                         if (!end || *end || !deepen_since ||
713                             /* revisions.c's max_age -1 is special */
714                             deepen_since == -1)
715                                 die("Invalid deepen-since: %s", line);
716                         deepen_rev_list = 1;
717                         continue;
718                 }
719                 if (skip_prefix(line, "deepen-not ", &arg)) {
720                         char *ref = NULL;
721                         unsigned char sha1[20];
722                         if (expand_ref(arg, strlen(arg), sha1, &ref) != 1)
723                                 die("git upload-pack: ambiguous deepen-not: %s", line);
724                         string_list_append(&deepen_not, ref);
725                         free(ref);
726                         deepen_rev_list = 1;
727                         continue;
728                 }
729                 if (!skip_prefix(line, "want ", &arg) ||
730                     get_sha1_hex(arg, sha1_buf))
731                         die("git upload-pack: protocol error, "
732                             "expected to get sha, not '%s'", line);
733
734                 features = arg + 40;
735
736                 if (parse_feature_request(features, "multi_ack_detailed"))
737                         multi_ack = 2;
738                 else if (parse_feature_request(features, "multi_ack"))
739                         multi_ack = 1;
740                 if (parse_feature_request(features, "no-done"))
741                         no_done = 1;
742                 if (parse_feature_request(features, "thin-pack"))
743                         use_thin_pack = 1;
744                 if (parse_feature_request(features, "ofs-delta"))
745                         use_ofs_delta = 1;
746                 if (parse_feature_request(features, "side-band-64k"))
747                         use_sideband = LARGE_PACKET_MAX;
748                 else if (parse_feature_request(features, "side-band"))
749                         use_sideband = DEFAULT_PACKET_MAX;
750                 if (parse_feature_request(features, "no-progress"))
751                         no_progress = 1;
752                 if (parse_feature_request(features, "include-tag"))
753                         use_include_tag = 1;
754
755                 o = parse_object(sha1_buf);
756                 if (!o)
757                         die("git upload-pack: not our ref %s",
758                             sha1_to_hex(sha1_buf));
759                 if (!(o->flags & WANTED)) {
760                         o->flags |= WANTED;
761                         if (!is_our_ref(o))
762                                 has_non_tip = 1;
763                         add_object_array(o, NULL, &want_obj);
764                 }
765         }
766
767         /*
768          * We have sent all our refs already, and the other end
769          * should have chosen out of them. When we are operating
770          * in the stateless RPC mode, however, their choice may
771          * have been based on the set of older refs advertised
772          * by another process that handled the initial request.
773          */
774         if (has_non_tip)
775                 check_non_tip();
776
777         if (!use_sideband && daemon_mode)
778                 no_progress = 1;
779
780         if (depth == 0 && !deepen_rev_list && shallows.nr == 0)
781                 return;
782         if (depth > 0 && deepen_rev_list)
783                 die("git upload-pack: deepen and deepen-since (or deepen-not) cannot be used together");
784         if (depth > 0)
785                 deepen(depth, &shallows);
786         else if (deepen_rev_list) {
787                 struct argv_array av = ARGV_ARRAY_INIT;
788                 int i;
789
790                 argv_array_push(&av, "rev-list");
791                 if (deepen_since)
792                         argv_array_pushf(&av, "--max-age=%lu", deepen_since);
793                 if (deepen_not.nr) {
794                         argv_array_push(&av, "--not");
795                         for (i = 0; i < deepen_not.nr; i++) {
796                                 struct string_list_item *s = deepen_not.items + i;
797                                 argv_array_push(&av, s->string);
798                         }
799                         argv_array_push(&av, "--not");
800                 }
801                 for (i = 0; i < want_obj.nr; i++) {
802                         struct object *o = want_obj.objects[i].item;
803                         argv_array_push(&av, oid_to_hex(&o->oid));
804                 }
805                 deepen_by_rev_list(av.argc, av.argv, &shallows);
806                 argv_array_clear(&av);
807         }
808         else
809                 if (shallows.nr > 0) {
810                         int i;
811                         for (i = 0; i < shallows.nr; i++)
812                                 register_shallow(shallows.objects[i].item->oid.hash);
813                 }
814
815         shallow_nr += shallows.nr;
816         free(shallows.objects);
817 }
818
819 /* return non-zero if the ref is hidden, otherwise 0 */
820 static int mark_our_ref(const char *refname, const char *refname_full,
821                         const struct object_id *oid)
822 {
823         struct object *o = lookup_unknown_object(oid->hash);
824
825         if (ref_is_hidden(refname, refname_full)) {
826                 o->flags |= HIDDEN_REF;
827                 return 1;
828         }
829         o->flags |= OUR_REF;
830         return 0;
831 }
832
833 static int check_ref(const char *refname_full, const struct object_id *oid,
834                      int flag, void *cb_data)
835 {
836         const char *refname = strip_namespace(refname_full);
837
838         mark_our_ref(refname, refname_full, oid);
839         return 0;
840 }
841
842 static void format_symref_info(struct strbuf *buf, struct string_list *symref)
843 {
844         struct string_list_item *item;
845
846         if (!symref->nr)
847                 return;
848         for_each_string_list_item(item, symref)
849                 strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
850 }
851
852 static int send_ref(const char *refname, const struct object_id *oid,
853                     int flag, void *cb_data)
854 {
855         static const char *capabilities = "multi_ack thin-pack side-band"
856                 " side-band-64k ofs-delta shallow deepen-since deepen-not no-progress"
857                 " include-tag multi_ack_detailed";
858         const char *refname_nons = strip_namespace(refname);
859         struct object_id peeled;
860
861         if (mark_our_ref(refname_nons, refname, oid))
862                 return 0;
863
864         if (capabilities) {
865                 struct strbuf symref_info = STRBUF_INIT;
866
867                 format_symref_info(&symref_info, cb_data);
868                 packet_write(1, "%s %s%c%s%s%s%s%s agent=%s\n",
869                              oid_to_hex(oid), refname_nons,
870                              0, capabilities,
871                              (allow_unadvertised_object_request & ALLOW_TIP_SHA1) ?
872                                      " allow-tip-sha1-in-want" : "",
873                              (allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1) ?
874                                      " allow-reachable-sha1-in-want" : "",
875                              stateless_rpc ? " no-done" : "",
876                              symref_info.buf,
877                              git_user_agent_sanitized());
878                 strbuf_release(&symref_info);
879         } else {
880                 packet_write(1, "%s %s\n", oid_to_hex(oid), refname_nons);
881         }
882         capabilities = NULL;
883         if (!peel_ref(refname, peeled.hash))
884                 packet_write(1, "%s %s^{}\n", oid_to_hex(&peeled), refname_nons);
885         return 0;
886 }
887
888 static int find_symref(const char *refname, const struct object_id *oid,
889                        int flag, void *cb_data)
890 {
891         const char *symref_target;
892         struct string_list_item *item;
893         struct object_id unused;
894
895         if ((flag & REF_ISSYMREF) == 0)
896                 return 0;
897         symref_target = resolve_ref_unsafe(refname, 0, unused.hash, &flag);
898         if (!symref_target || (flag & REF_ISSYMREF) == 0)
899                 die("'%s' is a symref but it is not?", refname);
900         item = string_list_append(cb_data, refname);
901         item->util = xstrdup(symref_target);
902         return 0;
903 }
904
905 static void upload_pack(void)
906 {
907         struct string_list symref = STRING_LIST_INIT_DUP;
908
909         head_ref_namespaced(find_symref, &symref);
910
911         if (advertise_refs || !stateless_rpc) {
912                 reset_timeout();
913                 head_ref_namespaced(send_ref, &symref);
914                 for_each_namespaced_ref(send_ref, &symref);
915                 advertise_shallow_grafts(1);
916                 packet_flush(1);
917         } else {
918                 head_ref_namespaced(check_ref, NULL);
919                 for_each_namespaced_ref(check_ref, NULL);
920         }
921         string_list_clear(&symref, 1);
922         if (advertise_refs)
923                 return;
924
925         receive_needs();
926         if (want_obj.nr) {
927                 get_common_commits();
928                 create_pack_file();
929         }
930 }
931
932 static int upload_pack_config(const char *var, const char *value, void *unused)
933 {
934         if (!strcmp("uploadpack.allowtipsha1inwant", var)) {
935                 if (git_config_bool(var, value))
936                         allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
937                 else
938                         allow_unadvertised_object_request &= ~ALLOW_TIP_SHA1;
939         } else if (!strcmp("uploadpack.allowreachablesha1inwant", var)) {
940                 if (git_config_bool(var, value))
941                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
942                 else
943                         allow_unadvertised_object_request &= ~ALLOW_REACHABLE_SHA1;
944         } else if (!strcmp("uploadpack.keepalive", var)) {
945                 keepalive = git_config_int(var, value);
946                 if (!keepalive)
947                         keepalive = -1;
948         }
949         return parse_hide_refs_config(var, value, "uploadpack");
950 }
951
952 int main(int argc, char **argv)
953 {
954         char *dir;
955         int i;
956         int strict = 0;
957
958         git_setup_gettext();
959
960         packet_trace_identity("upload-pack");
961         git_extract_argv0_path(argv[0]);
962         check_replace_refs = 0;
963
964         for (i = 1; i < argc; i++) {
965                 const char *arg = argv[i];
966
967                 if (arg[0] != '-')
968                         break;
969                 if (!strcmp(arg, "--advertise-refs")) {
970                         advertise_refs = 1;
971                         continue;
972                 }
973                 if (!strcmp(arg, "--stateless-rpc")) {
974                         stateless_rpc = 1;
975                         continue;
976                 }
977                 if (!strcmp(arg, "--strict")) {
978                         strict = 1;
979                         continue;
980                 }
981                 if (skip_prefix(arg, "--timeout=", &arg)) {
982                         timeout = atoi(arg);
983                         daemon_mode = 1;
984                         continue;
985                 }
986                 if (!strcmp(arg, "--")) {
987                         i++;
988                         break;
989                 }
990         }
991
992         if (i != argc-1)
993                 usage(upload_pack_usage);
994
995         setup_path();
996
997         dir = argv[i];
998
999         if (!enter_repo(dir, strict))
1000                 die("'%s' does not appear to be a git repository", dir);
1001
1002         git_config(upload_pack_config, NULL);
1003         upload_pack();
1004         return 0;
1005 }