Merge branch 'maint'
[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
13 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
14
15 /* bits #0..7 in revision.h, #8..10 in commit.c */
16 #define THEY_HAVE       (1u << 11)
17 #define OUR_REF         (1u << 12)
18 #define WANTED          (1u << 13)
19 #define COMMON_KNOWN    (1u << 14)
20 #define REACHABLE       (1u << 15)
21
22 #define SHALLOW         (1u << 16)
23 #define NOT_SHALLOW     (1u << 17)
24 #define CLIENT_SHALLOW  (1u << 18)
25
26 static unsigned long oldest_have;
27
28 static int multi_ack, nr_our_refs;
29 static int use_thin_pack, use_ofs_delta;
30 static struct object_array have_obj;
31 static struct object_array want_obj;
32 static unsigned int timeout;
33 /* 0 for no sideband,
34  * otherwise maximum packet size (up to 65520 bytes).
35  */
36 static int use_sideband;
37
38 static void reset_timeout(void)
39 {
40         alarm(timeout);
41 }
42
43 static int strip(char *line, int len)
44 {
45         if (len && line[len-1] == '\n')
46                 line[--len] = 0;
47         return len;
48 }
49
50 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
51 {
52         if (use_sideband)
53                 return send_sideband(1, fd, data, sz, use_sideband);
54         if (fd == 3)
55                 /* emergency quit */
56                 fd = 2;
57         if (fd == 2) {
58                 /* XXX: are we happy to lose stuff here? */
59                 xwrite(fd, data, sz);
60                 return sz;
61         }
62         return safe_write(fd, data, sz);
63 }
64
65 FILE *pack_pipe = NULL;
66 static void show_commit(struct commit *commit)
67 {
68         if (commit->object.flags & BOUNDARY)
69                 fputc('-', pack_pipe);
70         if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
71                 die("broken output pipe");
72         fputc('\n', pack_pipe);
73         fflush(pack_pipe);
74         free(commit->buffer);
75         commit->buffer = NULL;
76 }
77
78 static void show_object(struct object_array_entry *p)
79 {
80         /* An object with name "foo\n0000000..." can be used to
81          * confuse downstream git-pack-objects very badly.
82          */
83         const char *ep = strchr(p->name, '\n');
84         if (ep) {
85                 fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
86                        (int) (ep - p->name),
87                        p->name);
88         }
89         else
90                 fprintf(pack_pipe, "%s %s\n",
91                                 sha1_to_hex(p->item->sha1), p->name);
92 }
93
94 static void show_edge(struct commit *commit)
95 {
96         fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
97 }
98
99 static void create_pack_file(void)
100 {
101         /* Pipes between rev-list to pack-objects, pack-objects to us
102          * and pack-objects error stream for progress bar.
103          */
104         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
105         pid_t pid_rev_list, pid_pack_objects;
106         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
107         char data[8193], progress[128];
108         char abort_msg[] = "aborting due to possible repository "
109                 "corruption on the remote side.";
110         int buffered = -1;
111
112         if (pipe(lp_pipe) < 0)
113                 die("git-upload-pack: unable to create pipe");
114         pid_rev_list = fork();
115         if (pid_rev_list < 0)
116                 die("git-upload-pack: unable to fork git-rev-list");
117
118         if (!pid_rev_list) {
119                 int i;
120                 struct rev_info revs;
121
122                 pack_pipe = fdopen(lp_pipe[1], "w");
123
124                 if (create_full_pack)
125                         use_thin_pack = 0; /* no point doing it */
126                 init_revisions(&revs, NULL);
127                 revs.tag_objects = 1;
128                 revs.tree_objects = 1;
129                 revs.blob_objects = 1;
130                 if (use_thin_pack)
131                         revs.edge_hint = 1;
132
133                 if (create_full_pack) {
134                         const char *args[] = {"rev-list", "--all", NULL};
135                         setup_revisions(2, args, &revs, NULL);
136                 } else {
137                         for (i = 0; i < want_obj.nr; i++) {
138                                 struct object *o = want_obj.objects[i].item;
139                                 /* why??? */
140                                 o->flags &= ~UNINTERESTING;
141                                 add_pending_object(&revs, o, NULL);
142                         }
143                         for (i = 0; i < have_obj.nr; i++) {
144                                 struct object *o = have_obj.objects[i].item;
145                                 o->flags |= UNINTERESTING;
146                                 add_pending_object(&revs, o, NULL);
147                         }
148                         setup_revisions(0, NULL, &revs, NULL);
149                 }
150                 prepare_revision_walk(&revs);
151                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
152                 traverse_commit_list(&revs, show_commit, show_object);
153                 exit(0);
154         }
155
156         if (pipe(pu_pipe) < 0)
157                 die("git-upload-pack: unable to create pipe");
158         if (pipe(pe_pipe) < 0)
159                 die("git-upload-pack: unable to create pipe");
160         pid_pack_objects = fork();
161         if (pid_pack_objects < 0) {
162                 /* daemon sets things up to ignore TERM */
163                 kill(pid_rev_list, SIGKILL);
164                 die("git-upload-pack: unable to fork git-pack-objects");
165         }
166         if (!pid_pack_objects) {
167                 dup2(lp_pipe[0], 0);
168                 dup2(pu_pipe[1], 1);
169                 dup2(pe_pipe[1], 2);
170
171                 close(lp_pipe[0]);
172                 close(lp_pipe[1]);
173                 close(pu_pipe[0]);
174                 close(pu_pipe[1]);
175                 close(pe_pipe[0]);
176                 close(pe_pipe[1]);
177                 execl_git_cmd("pack-objects", "--stdout", "--progress",
178                               use_ofs_delta ? "--delta-base-offset" : NULL,
179                               NULL);
180                 kill(pid_rev_list, SIGKILL);
181                 die("git-upload-pack: unable to exec git-pack-objects");
182         }
183
184         close(lp_pipe[0]);
185         close(lp_pipe[1]);
186
187         /* We read from pe_pipe[0] to capture stderr output for
188          * progress bar, and pu_pipe[0] to capture the pack data.
189          */
190         close(pe_pipe[1]);
191         close(pu_pipe[1]);
192
193         while (1) {
194                 const char *who;
195                 struct pollfd pfd[2];
196                 pid_t pid;
197                 int status;
198                 ssize_t sz;
199                 int pe, pu, pollsize;
200
201                 reset_timeout();
202
203                 pollsize = 0;
204                 pe = pu = -1;
205
206                 if (0 <= pu_pipe[0]) {
207                         pfd[pollsize].fd = pu_pipe[0];
208                         pfd[pollsize].events = POLLIN;
209                         pu = pollsize;
210                         pollsize++;
211                 }
212                 if (0 <= pe_pipe[0]) {
213                         pfd[pollsize].fd = pe_pipe[0];
214                         pfd[pollsize].events = POLLIN;
215                         pe = pollsize;
216                         pollsize++;
217                 }
218
219                 if (pollsize) {
220                         if (poll(pfd, pollsize, -1) < 0) {
221                                 if (errno != EINTR) {
222                                         error("poll failed, resuming: %s",
223                                               strerror(errno));
224                                         sleep(1);
225                                 }
226                                 continue;
227                         }
228                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
229                                 /* Data ready; we keep the last byte
230                                  * to ourselves in case we detect
231                                  * broken rev-list, so that we can
232                                  * leave the stream corrupted.  This
233                                  * is unfortunate -- unpack-objects
234                                  * would happily accept a valid pack
235                                  * data with trailing garbage, so
236                                  * appending garbage after we pass all
237                                  * the pack data is not good enough to
238                                  * signal breakage to downstream.
239                                  */
240                                 char *cp = data;
241                                 ssize_t outsz = 0;
242                                 if (0 <= buffered) {
243                                         *cp++ = buffered;
244                                         outsz++;
245                                 }
246                                 sz = xread(pu_pipe[0], cp,
247                                           sizeof(data) - outsz);
248                                 if (0 < sz)
249                                                 ;
250                                 else if (sz == 0) {
251                                         close(pu_pipe[0]);
252                                         pu_pipe[0] = -1;
253                                 }
254                                 else
255                                         goto fail;
256                                 sz += outsz;
257                                 if (1 < sz) {
258                                         buffered = data[sz-1] & 0xFF;
259                                         sz--;
260                                 }
261                                 else
262                                         buffered = -1;
263                                 sz = send_client_data(1, data, sz);
264                                 if (sz < 0)
265                                         goto fail;
266                         }
267                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
268                                 /* Status ready; we ship that in the side-band
269                                  * or dump to the standard error.
270                                  */
271                                 sz = xread(pe_pipe[0], progress,
272                                           sizeof(progress));
273                                 if (0 < sz)
274                                         send_client_data(2, progress, sz);
275                                 else if (sz == 0) {
276                                         close(pe_pipe[0]);
277                                         pe_pipe[0] = -1;
278                                 }
279                                 else
280                                         goto fail;
281                         }
282                 }
283
284                 /* See if the children are still there */
285                 if (pid_rev_list || pid_pack_objects) {
286                         pid = waitpid(-1, &status, WNOHANG);
287                         if (!pid)
288                                 continue;
289                         who = ((pid == pid_rev_list) ? "git-rev-list" :
290                                (pid == pid_pack_objects) ? "git-pack-objects" :
291                                NULL);
292                         if (!who) {
293                                 if (pid < 0) {
294                                         error("git-upload-pack: %s",
295                                               strerror(errno));
296                                         goto fail;
297                                 }
298                                 error("git-upload-pack: we weren't "
299                                       "waiting for %d", pid);
300                                 continue;
301                         }
302                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
303                                 error("git-upload-pack: %s died with error.",
304                                       who);
305                                 goto fail;
306                         }
307                         if (pid == pid_rev_list)
308                                 pid_rev_list = 0;
309                         if (pid == pid_pack_objects)
310                                 pid_pack_objects = 0;
311                         if (pid_rev_list || pid_pack_objects)
312                                 continue;
313                 }
314
315                 /* both died happily */
316                 if (pollsize)
317                         continue;
318
319                 /* flush the data */
320                 if (0 <= buffered) {
321                         data[0] = buffered;
322                         sz = send_client_data(1, data, 1);
323                         if (sz < 0)
324                                 goto fail;
325                         fprintf(stderr, "flushed.\n");
326                 }
327                 if (use_sideband)
328                         packet_flush(1);
329                 return;
330         }
331  fail:
332         if (pid_pack_objects)
333                 kill(pid_pack_objects, SIGKILL);
334         if (pid_rev_list)
335                 kill(pid_rev_list, SIGKILL);
336         send_client_data(3, abort_msg, sizeof(abort_msg));
337         die("git-upload-pack: %s", abort_msg);
338 }
339
340 static int got_sha1(char *hex, unsigned char *sha1)
341 {
342         struct object *o;
343         int we_knew_they_have = 0;
344
345         if (get_sha1_hex(hex, sha1))
346                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
347         if (!has_sha1_file(sha1))
348                 return -1;
349
350         o = lookup_object(sha1);
351         if (!(o && o->parsed))
352                 o = parse_object(sha1);
353         if (!o)
354                 die("oops (%s)", sha1_to_hex(sha1));
355         if (o->type == OBJ_COMMIT) {
356                 struct commit_list *parents;
357                 struct commit *commit = (struct commit *)o;
358                 if (o->flags & THEY_HAVE)
359                         we_knew_they_have = 1;
360                 else
361                         o->flags |= THEY_HAVE;
362                 if (!oldest_have || (commit->date < oldest_have))
363                         oldest_have = commit->date;
364                 for (parents = commit->parents;
365                      parents;
366                      parents = parents->next)
367                         parents->item->object.flags |= THEY_HAVE;
368         }
369         if (!we_knew_they_have) {
370                 add_object_array(o, NULL, &have_obj);
371                 return 1;
372         }
373         return 0;
374 }
375
376 static int reachable(struct commit *want)
377 {
378         struct commit_list *work = NULL;
379
380         insert_by_date(want, &work);
381         while (work) {
382                 struct commit_list *list = work->next;
383                 struct commit *commit = work->item;
384                 free(work);
385                 work = list;
386
387                 if (commit->object.flags & THEY_HAVE) {
388                         want->object.flags |= COMMON_KNOWN;
389                         break;
390                 }
391                 if (!commit->object.parsed)
392                         parse_object(commit->object.sha1);
393                 if (commit->object.flags & REACHABLE)
394                         continue;
395                 commit->object.flags |= REACHABLE;
396                 if (commit->date < oldest_have)
397                         continue;
398                 for (list = commit->parents; list; list = list->next) {
399                         struct commit *parent = list->item;
400                         if (!(parent->object.flags & REACHABLE))
401                                 insert_by_date(parent, &work);
402                 }
403         }
404         want->object.flags |= REACHABLE;
405         clear_commit_marks(want, REACHABLE);
406         free_commit_list(work);
407         return (want->object.flags & COMMON_KNOWN);
408 }
409
410 static int ok_to_give_up(void)
411 {
412         int i;
413
414         if (!have_obj.nr)
415                 return 0;
416
417         for (i = 0; i < want_obj.nr; i++) {
418                 struct object *want = want_obj.objects[i].item;
419
420                 if (want->flags & COMMON_KNOWN)
421                         continue;
422                 want = deref_tag(want, "a want line", 0);
423                 if (!want || want->type != OBJ_COMMIT) {
424                         /* no way to tell if this is reachable by
425                          * looking at the ancestry chain alone, so
426                          * leave a note to ourselves not to worry about
427                          * this object anymore.
428                          */
429                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
430                         continue;
431                 }
432                 if (!reachable((struct commit *)want))
433                         return 0;
434         }
435         return 1;
436 }
437
438 static int get_common_commits(void)
439 {
440         static char line[1000];
441         unsigned char sha1[20];
442         char hex[41], last_hex[41];
443         int len;
444
445         track_object_refs = 0;
446         save_commit_buffer = 0;
447
448         for(;;) {
449                 len = packet_read_line(0, line, sizeof(line));
450                 reset_timeout();
451
452                 if (!len) {
453                         if (have_obj.nr == 0 || multi_ack)
454                                 packet_write(1, "NAK\n");
455                         continue;
456                 }
457                 len = strip(line, len);
458                 if (!prefixcmp(line, "have ")) {
459                         switch (got_sha1(line+5, sha1)) {
460                         case -1: /* they have what we do not */
461                                 if (multi_ack && ok_to_give_up())
462                                         packet_write(1, "ACK %s continue\n",
463                                                      sha1_to_hex(sha1));
464                                 break;
465                         default:
466                                 memcpy(hex, sha1_to_hex(sha1), 41);
467                                 if (multi_ack) {
468                                         const char *msg = "ACK %s continue\n";
469                                         packet_write(1, msg, hex);
470                                         memcpy(last_hex, hex, 41);
471                                 }
472                                 else if (have_obj.nr == 1)
473                                         packet_write(1, "ACK %s\n", hex);
474                                 break;
475                         }
476                         continue;
477                 }
478                 if (!strcmp(line, "done")) {
479                         if (have_obj.nr > 0) {
480                                 if (multi_ack)
481                                         packet_write(1, "ACK %s\n", last_hex);
482                                 return 0;
483                         }
484                         packet_write(1, "NAK\n");
485                         return -1;
486                 }
487                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
488         }
489 }
490
491 static void receive_needs(void)
492 {
493         struct object_array shallows = {0, 0, NULL};
494         static char line[1000];
495         int len, depth = 0;
496
497         for (;;) {
498                 struct object *o;
499                 unsigned char sha1_buf[20];
500                 len = packet_read_line(0, line, sizeof(line));
501                 reset_timeout();
502                 if (!len)
503                         break;
504
505                 if (!prefixcmp(line, "shallow ")) {
506                         unsigned char sha1[20];
507                         struct object *object;
508                         use_thin_pack = 0;
509                         if (get_sha1(line + 8, sha1))
510                                 die("invalid shallow line: %s", line);
511                         object = parse_object(sha1);
512                         if (!object)
513                                 die("did not find object for %s", line);
514                         object->flags |= CLIENT_SHALLOW;
515                         add_object_array(object, NULL, &shallows);
516                         continue;
517                 }
518                 if (!prefixcmp(line, "deepen ")) {
519                         char *end;
520                         use_thin_pack = 0;
521                         depth = strtol(line + 7, &end, 0);
522                         if (end == line + 7 || depth <= 0)
523                                 die("Invalid deepen: %s", line);
524                         continue;
525                 }
526                 if (prefixcmp(line, "want ") ||
527                     get_sha1_hex(line+5, sha1_buf))
528                         die("git-upload-pack: protocol error, "
529                             "expected to get sha, not '%s'", line);
530                 if (strstr(line+45, "multi_ack"))
531                         multi_ack = 1;
532                 if (strstr(line+45, "thin-pack"))
533                         use_thin_pack = 1;
534                 if (strstr(line+45, "ofs-delta"))
535                         use_ofs_delta = 1;
536                 if (strstr(line+45, "side-band-64k"))
537                         use_sideband = LARGE_PACKET_MAX;
538                 else if (strstr(line+45, "side-band"))
539                         use_sideband = DEFAULT_PACKET_MAX;
540
541                 /* We have sent all our refs already, and the other end
542                  * should have chosen out of them; otherwise they are
543                  * asking for nonsense.
544                  *
545                  * Hmph.  We may later want to allow "want" line that
546                  * asks for something like "master~10" (symbolic)...
547                  * would it make sense?  I don't know.
548                  */
549                 o = lookup_object(sha1_buf);
550                 if (!o || !(o->flags & OUR_REF))
551                         die("git-upload-pack: not our ref %s", line+5);
552                 if (!(o->flags & WANTED)) {
553                         o->flags |= WANTED;
554                         add_object_array(o, NULL, &want_obj);
555                 }
556         }
557         if (depth == 0 && shallows.nr == 0)
558                 return;
559         if (depth > 0) {
560                 struct commit_list *result, *backup;
561                 int i;
562                 backup = result = get_shallow_commits(&want_obj, depth,
563                         SHALLOW, NOT_SHALLOW);
564                 while (result) {
565                         struct object *object = &result->item->object;
566                         if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
567                                 packet_write(1, "shallow %s",
568                                                 sha1_to_hex(object->sha1));
569                                 register_shallow(object->sha1);
570                         }
571                         result = result->next;
572                 }
573                 free_commit_list(backup);
574                 for (i = 0; i < shallows.nr; i++) {
575                         struct object *object = shallows.objects[i].item;
576                         if (object->flags & NOT_SHALLOW) {
577                                 struct commit_list *parents;
578                                 packet_write(1, "unshallow %s",
579                                         sha1_to_hex(object->sha1));
580                                 object->flags &= ~CLIENT_SHALLOW;
581                                 /* make sure the real parents are parsed */
582                                 unregister_shallow(object->sha1);
583                                 object->parsed = 0;
584                                 parse_commit((struct commit *)object);
585                                 parents = ((struct commit *)object)->parents;
586                                 while (parents) {
587                                         add_object_array(&parents->item->object,
588                                                         NULL, &want_obj);
589                                         parents = parents->next;
590                                 }
591                         }
592                         /* make sure commit traversal conforms to client */
593                         register_shallow(object->sha1);
594                 }
595                 packet_flush(1);
596         } else
597                 if (shallows.nr > 0) {
598                         int i;
599                         for (i = 0; i < shallows.nr; i++)
600                                 register_shallow(shallows.objects[i].item->sha1);
601                 }
602         free(shallows.objects);
603 }
604
605 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
606 {
607         static const char *capabilities = "multi_ack thin-pack side-band"
608                 " side-band-64k ofs-delta shallow";
609         struct object *o = parse_object(sha1);
610
611         if (!o)
612                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
613
614         if (capabilities)
615                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
616                         0, capabilities);
617         else
618                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
619         capabilities = NULL;
620         if (!(o->flags & OUR_REF)) {
621                 o->flags |= OUR_REF;
622                 nr_our_refs++;
623         }
624         if (o->type == OBJ_TAG) {
625                 o = deref_tag(o, refname, 0);
626                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
627         }
628         return 0;
629 }
630
631 static void upload_pack(void)
632 {
633         reset_timeout();
634         head_ref(send_ref, NULL);
635         for_each_ref(send_ref, NULL);
636         packet_flush(1);
637         receive_needs();
638         if (want_obj.nr) {
639                 get_common_commits();
640                 create_pack_file();
641         }
642 }
643
644 int main(int argc, char **argv)
645 {
646         char *dir;
647         int i;
648         int strict = 0;
649
650         for (i = 1; i < argc; i++) {
651                 char *arg = argv[i];
652
653                 if (arg[0] != '-')
654                         break;
655                 if (!strcmp(arg, "--strict")) {
656                         strict = 1;
657                         continue;
658                 }
659                 if (!prefixcmp(arg, "--timeout=")) {
660                         timeout = atoi(arg+10);
661                         continue;
662                 }
663                 if (!strcmp(arg, "--")) {
664                         i++;
665                         break;
666                 }
667         }
668         
669         if (i != argc-1)
670                 usage(upload_pack_usage);
671         dir = argv[i];
672
673         if (!enter_repo(dir, strict))
674                 die("'%s': unable to chdir or not a git archive", dir);
675         if (is_repository_shallow())
676                 die("attempt to fetch/clone from a shallow repository");
677         upload_pack();
678         return 0;
679 }