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, no_progress;
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                 const char *argv[10];
168                 int i = 0;
169
170                 dup2(lp_pipe[0], 0);
171                 dup2(pu_pipe[1], 1);
172                 dup2(pe_pipe[1], 2);
173
174                 close(lp_pipe[0]);
175                 close(lp_pipe[1]);
176                 close(pu_pipe[0]);
177                 close(pu_pipe[1]);
178                 close(pe_pipe[0]);
179                 close(pe_pipe[1]);
180
181                 argv[i++] = "pack-objects";
182                 argv[i++] = "--stdout";
183                 if (!no_progress)
184                         argv[i++] = "--progress";
185                 if (use_ofs_delta)
186                         argv[i++] = "--delta-base-offset";
187                 argv[i++] = NULL;
188
189                 execv_git_cmd(argv);
190                 kill(pid_rev_list, SIGKILL);
191                 die("git-upload-pack: unable to exec git-pack-objects");
192         }
193
194         close(lp_pipe[0]);
195         close(lp_pipe[1]);
196
197         /* We read from pe_pipe[0] to capture stderr output for
198          * progress bar, and pu_pipe[0] to capture the pack data.
199          */
200         close(pe_pipe[1]);
201         close(pu_pipe[1]);
202
203         while (1) {
204                 const char *who;
205                 struct pollfd pfd[2];
206                 pid_t pid;
207                 int status;
208                 ssize_t sz;
209                 int pe, pu, pollsize;
210
211                 reset_timeout();
212
213                 pollsize = 0;
214                 pe = pu = -1;
215
216                 if (0 <= pu_pipe[0]) {
217                         pfd[pollsize].fd = pu_pipe[0];
218                         pfd[pollsize].events = POLLIN;
219                         pu = pollsize;
220                         pollsize++;
221                 }
222                 if (0 <= pe_pipe[0]) {
223                         pfd[pollsize].fd = pe_pipe[0];
224                         pfd[pollsize].events = POLLIN;
225                         pe = pollsize;
226                         pollsize++;
227                 }
228
229                 if (pollsize) {
230                         if (poll(pfd, pollsize, -1) < 0) {
231                                 if (errno != EINTR) {
232                                         error("poll failed, resuming: %s",
233                                               strerror(errno));
234                                         sleep(1);
235                                 }
236                                 continue;
237                         }
238                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
239                                 /* Data ready; we keep the last byte
240                                  * to ourselves in case we detect
241                                  * broken rev-list, so that we can
242                                  * leave the stream corrupted.  This
243                                  * is unfortunate -- unpack-objects
244                                  * would happily accept a valid pack
245                                  * data with trailing garbage, so
246                                  * appending garbage after we pass all
247                                  * the pack data is not good enough to
248                                  * signal breakage to downstream.
249                                  */
250                                 char *cp = data;
251                                 ssize_t outsz = 0;
252                                 if (0 <= buffered) {
253                                         *cp++ = buffered;
254                                         outsz++;
255                                 }
256                                 sz = xread(pu_pipe[0], cp,
257                                           sizeof(data) - outsz);
258                                 if (0 < sz)
259                                                 ;
260                                 else if (sz == 0) {
261                                         close(pu_pipe[0]);
262                                         pu_pipe[0] = -1;
263                                 }
264                                 else
265                                         goto fail;
266                                 sz += outsz;
267                                 if (1 < sz) {
268                                         buffered = data[sz-1] & 0xFF;
269                                         sz--;
270                                 }
271                                 else
272                                         buffered = -1;
273                                 sz = send_client_data(1, data, sz);
274                                 if (sz < 0)
275                                         goto fail;
276                         }
277                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
278                                 /* Status ready; we ship that in the side-band
279                                  * or dump to the standard error.
280                                  */
281                                 sz = xread(pe_pipe[0], progress,
282                                           sizeof(progress));
283                                 if (0 < sz)
284                                         send_client_data(2, progress, sz);
285                                 else if (sz == 0) {
286                                         close(pe_pipe[0]);
287                                         pe_pipe[0] = -1;
288                                 }
289                                 else
290                                         goto fail;
291                         }
292                 }
293
294                 /* See if the children are still there */
295                 if (pid_rev_list || pid_pack_objects) {
296                         pid = waitpid(-1, &status, WNOHANG);
297                         if (!pid)
298                                 continue;
299                         who = ((pid == pid_rev_list) ? "git-rev-list" :
300                                (pid == pid_pack_objects) ? "git-pack-objects" :
301                                NULL);
302                         if (!who) {
303                                 if (pid < 0) {
304                                         error("git-upload-pack: %s",
305                                               strerror(errno));
306                                         goto fail;
307                                 }
308                                 error("git-upload-pack: we weren't "
309                                       "waiting for %d", pid);
310                                 continue;
311                         }
312                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
313                                 error("git-upload-pack: %s died with error.",
314                                       who);
315                                 goto fail;
316                         }
317                         if (pid == pid_rev_list)
318                                 pid_rev_list = 0;
319                         if (pid == pid_pack_objects)
320                                 pid_pack_objects = 0;
321                         if (pid_rev_list || pid_pack_objects)
322                                 continue;
323                 }
324
325                 /* both died happily */
326                 if (pollsize)
327                         continue;
328
329                 /* flush the data */
330                 if (0 <= buffered) {
331                         data[0] = buffered;
332                         sz = send_client_data(1, data, 1);
333                         if (sz < 0)
334                                 goto fail;
335                         fprintf(stderr, "flushed.\n");
336                 }
337                 if (use_sideband)
338                         packet_flush(1);
339                 return;
340         }
341  fail:
342         if (pid_pack_objects)
343                 kill(pid_pack_objects, SIGKILL);
344         if (pid_rev_list)
345                 kill(pid_rev_list, SIGKILL);
346         send_client_data(3, abort_msg, sizeof(abort_msg));
347         die("git-upload-pack: %s", abort_msg);
348 }
349
350 static int got_sha1(char *hex, unsigned char *sha1)
351 {
352         struct object *o;
353         int we_knew_they_have = 0;
354
355         if (get_sha1_hex(hex, sha1))
356                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
357         if (!has_sha1_file(sha1))
358                 return -1;
359
360         o = lookup_object(sha1);
361         if (!(o && o->parsed))
362                 o = parse_object(sha1);
363         if (!o)
364                 die("oops (%s)", sha1_to_hex(sha1));
365         if (o->type == OBJ_COMMIT) {
366                 struct commit_list *parents;
367                 struct commit *commit = (struct commit *)o;
368                 if (o->flags & THEY_HAVE)
369                         we_knew_they_have = 1;
370                 else
371                         o->flags |= THEY_HAVE;
372                 if (!oldest_have || (commit->date < oldest_have))
373                         oldest_have = commit->date;
374                 for (parents = commit->parents;
375                      parents;
376                      parents = parents->next)
377                         parents->item->object.flags |= THEY_HAVE;
378         }
379         if (!we_knew_they_have) {
380                 add_object_array(o, NULL, &have_obj);
381                 return 1;
382         }
383         return 0;
384 }
385
386 static int reachable(struct commit *want)
387 {
388         struct commit_list *work = NULL;
389
390         insert_by_date(want, &work);
391         while (work) {
392                 struct commit_list *list = work->next;
393                 struct commit *commit = work->item;
394                 free(work);
395                 work = list;
396
397                 if (commit->object.flags & THEY_HAVE) {
398                         want->object.flags |= COMMON_KNOWN;
399                         break;
400                 }
401                 if (!commit->object.parsed)
402                         parse_object(commit->object.sha1);
403                 if (commit->object.flags & REACHABLE)
404                         continue;
405                 commit->object.flags |= REACHABLE;
406                 if (commit->date < oldest_have)
407                         continue;
408                 for (list = commit->parents; list; list = list->next) {
409                         struct commit *parent = list->item;
410                         if (!(parent->object.flags & REACHABLE))
411                                 insert_by_date(parent, &work);
412                 }
413         }
414         want->object.flags |= REACHABLE;
415         clear_commit_marks(want, REACHABLE);
416         free_commit_list(work);
417         return (want->object.flags & COMMON_KNOWN);
418 }
419
420 static int ok_to_give_up(void)
421 {
422         int i;
423
424         if (!have_obj.nr)
425                 return 0;
426
427         for (i = 0; i < want_obj.nr; i++) {
428                 struct object *want = want_obj.objects[i].item;
429
430                 if (want->flags & COMMON_KNOWN)
431                         continue;
432                 want = deref_tag(want, "a want line", 0);
433                 if (!want || want->type != OBJ_COMMIT) {
434                         /* no way to tell if this is reachable by
435                          * looking at the ancestry chain alone, so
436                          * leave a note to ourselves not to worry about
437                          * this object anymore.
438                          */
439                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
440                         continue;
441                 }
442                 if (!reachable((struct commit *)want))
443                         return 0;
444         }
445         return 1;
446 }
447
448 static int get_common_commits(void)
449 {
450         static char line[1000];
451         unsigned char sha1[20];
452         char hex[41], last_hex[41];
453         int len;
454
455         track_object_refs = 0;
456         save_commit_buffer = 0;
457
458         for(;;) {
459                 len = packet_read_line(0, line, sizeof(line));
460                 reset_timeout();
461
462                 if (!len) {
463                         if (have_obj.nr == 0 || multi_ack)
464                                 packet_write(1, "NAK\n");
465                         continue;
466                 }
467                 len = strip(line, len);
468                 if (!prefixcmp(line, "have ")) {
469                         switch (got_sha1(line+5, sha1)) {
470                         case -1: /* they have what we do not */
471                                 if (multi_ack && ok_to_give_up())
472                                         packet_write(1, "ACK %s continue\n",
473                                                      sha1_to_hex(sha1));
474                                 break;
475                         default:
476                                 memcpy(hex, sha1_to_hex(sha1), 41);
477                                 if (multi_ack) {
478                                         const char *msg = "ACK %s continue\n";
479                                         packet_write(1, msg, hex);
480                                         memcpy(last_hex, hex, 41);
481                                 }
482                                 else if (have_obj.nr == 1)
483                                         packet_write(1, "ACK %s\n", hex);
484                                 break;
485                         }
486                         continue;
487                 }
488                 if (!strcmp(line, "done")) {
489                         if (have_obj.nr > 0) {
490                                 if (multi_ack)
491                                         packet_write(1, "ACK %s\n", last_hex);
492                                 return 0;
493                         }
494                         packet_write(1, "NAK\n");
495                         return -1;
496                 }
497                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
498         }
499 }
500
501 static void receive_needs(void)
502 {
503         struct object_array shallows = {0, 0, NULL};
504         static char line[1000];
505         int len, depth = 0;
506
507         for (;;) {
508                 struct object *o;
509                 unsigned char sha1_buf[20];
510                 len = packet_read_line(0, line, sizeof(line));
511                 reset_timeout();
512                 if (!len)
513                         break;
514
515                 if (!prefixcmp(line, "shallow ")) {
516                         unsigned char sha1[20];
517                         struct object *object;
518                         use_thin_pack = 0;
519                         if (get_sha1(line + 8, sha1))
520                                 die("invalid shallow line: %s", line);
521                         object = parse_object(sha1);
522                         if (!object)
523                                 die("did not find object for %s", line);
524                         object->flags |= CLIENT_SHALLOW;
525                         add_object_array(object, NULL, &shallows);
526                         continue;
527                 }
528                 if (!prefixcmp(line, "deepen ")) {
529                         char *end;
530                         use_thin_pack = 0;
531                         depth = strtol(line + 7, &end, 0);
532                         if (end == line + 7 || depth <= 0)
533                                 die("Invalid deepen: %s", line);
534                         continue;
535                 }
536                 if (prefixcmp(line, "want ") ||
537                     get_sha1_hex(line+5, sha1_buf))
538                         die("git-upload-pack: protocol error, "
539                             "expected to get sha, not '%s'", line);
540                 if (strstr(line+45, "multi_ack"))
541                         multi_ack = 1;
542                 if (strstr(line+45, "thin-pack"))
543                         use_thin_pack = 1;
544                 if (strstr(line+45, "ofs-delta"))
545                         use_ofs_delta = 1;
546                 if (strstr(line+45, "side-band-64k"))
547                         use_sideband = LARGE_PACKET_MAX;
548                 else if (strstr(line+45, "side-band"))
549                         use_sideband = DEFAULT_PACKET_MAX;
550                 if (strstr(line+45, "no-progress"))
551                         no_progress = 1;
552
553                 /* We have sent all our refs already, and the other end
554                  * should have chosen out of them; otherwise they are
555                  * asking for nonsense.
556                  *
557                  * Hmph.  We may later want to allow "want" line that
558                  * asks for something like "master~10" (symbolic)...
559                  * would it make sense?  I don't know.
560                  */
561                 o = lookup_object(sha1_buf);
562                 if (!o || !(o->flags & OUR_REF))
563                         die("git-upload-pack: not our ref %s", line+5);
564                 if (!(o->flags & WANTED)) {
565                         o->flags |= WANTED;
566                         add_object_array(o, NULL, &want_obj);
567                 }
568         }
569         if (depth == 0 && shallows.nr == 0)
570                 return;
571         if (depth > 0) {
572                 struct commit_list *result, *backup;
573                 int i;
574                 backup = result = get_shallow_commits(&want_obj, depth,
575                         SHALLOW, NOT_SHALLOW);
576                 while (result) {
577                         struct object *object = &result->item->object;
578                         if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
579                                 packet_write(1, "shallow %s",
580                                                 sha1_to_hex(object->sha1));
581                                 register_shallow(object->sha1);
582                         }
583                         result = result->next;
584                 }
585                 free_commit_list(backup);
586                 for (i = 0; i < shallows.nr; i++) {
587                         struct object *object = shallows.objects[i].item;
588                         if (object->flags & NOT_SHALLOW) {
589                                 struct commit_list *parents;
590                                 packet_write(1, "unshallow %s",
591                                         sha1_to_hex(object->sha1));
592                                 object->flags &= ~CLIENT_SHALLOW;
593                                 /* make sure the real parents are parsed */
594                                 unregister_shallow(object->sha1);
595                                 object->parsed = 0;
596                                 parse_commit((struct commit *)object);
597                                 parents = ((struct commit *)object)->parents;
598                                 while (parents) {
599                                         add_object_array(&parents->item->object,
600                                                         NULL, &want_obj);
601                                         parents = parents->next;
602                                 }
603                         }
604                         /* make sure commit traversal conforms to client */
605                         register_shallow(object->sha1);
606                 }
607                 packet_flush(1);
608         } else
609                 if (shallows.nr > 0) {
610                         int i;
611                         for (i = 0; i < shallows.nr; i++)
612                                 register_shallow(shallows.objects[i].item->sha1);
613                 }
614         free(shallows.objects);
615 }
616
617 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
618 {
619         static const char *capabilities = "multi_ack thin-pack side-band"
620                 " side-band-64k ofs-delta shallow no-progress";
621         struct object *o = parse_object(sha1);
622
623         if (!o)
624                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
625
626         if (capabilities)
627                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
628                         0, capabilities);
629         else
630                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
631         capabilities = NULL;
632         if (!(o->flags & OUR_REF)) {
633                 o->flags |= OUR_REF;
634                 nr_our_refs++;
635         }
636         if (o->type == OBJ_TAG) {
637                 o = deref_tag(o, refname, 0);
638                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
639         }
640         return 0;
641 }
642
643 static void upload_pack(void)
644 {
645         reset_timeout();
646         head_ref(send_ref, NULL);
647         for_each_ref(send_ref, NULL);
648         packet_flush(1);
649         receive_needs();
650         if (want_obj.nr) {
651                 get_common_commits();
652                 create_pack_file();
653         }
654 }
655
656 int main(int argc, char **argv)
657 {
658         char *dir;
659         int i;
660         int strict = 0;
661
662         for (i = 1; i < argc; i++) {
663                 char *arg = argv[i];
664
665                 if (arg[0] != '-')
666                         break;
667                 if (!strcmp(arg, "--strict")) {
668                         strict = 1;
669                         continue;
670                 }
671                 if (!prefixcmp(arg, "--timeout=")) {
672                         timeout = atoi(arg+10);
673                         continue;
674                 }
675                 if (!strcmp(arg, "--")) {
676                         i++;
677                         break;
678                 }
679         }
680         
681         if (i != argc-1)
682                 usage(upload_pack_usage);
683         dir = argv[i];
684
685         if (!enter_repo(dir, strict))
686                 die("'%s': unable to chdir or not a git archive", dir);
687         if (is_repository_shallow())
688                 die("attempt to fetch/clone from a shallow repository");
689         upload_pack();
690         return 0;
691 }