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 static 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                 close(lp_pipe[0]);
123                 pack_pipe = fdopen(lp_pipe[1], "w");
124
125                 if (create_full_pack)
126                         use_thin_pack = 0; /* no point doing it */
127                 init_revisions(&revs, NULL);
128                 revs.tag_objects = 1;
129                 revs.tree_objects = 1;
130                 revs.blob_objects = 1;
131                 if (use_thin_pack)
132                         revs.edge_hint = 1;
133
134                 if (create_full_pack) {
135                         const char *args[] = {"rev-list", "--all", NULL};
136                         setup_revisions(2, args, &revs, NULL);
137                 } else {
138                         for (i = 0; i < want_obj.nr; i++) {
139                                 struct object *o = want_obj.objects[i].item;
140                                 /* why??? */
141                                 o->flags &= ~UNINTERESTING;
142                                 add_pending_object(&revs, o, NULL);
143                         }
144                         for (i = 0; i < have_obj.nr; i++) {
145                                 struct object *o = have_obj.objects[i].item;
146                                 o->flags |= UNINTERESTING;
147                                 add_pending_object(&revs, o, NULL);
148                         }
149                         setup_revisions(0, NULL, &revs, NULL);
150                 }
151                 prepare_revision_walk(&revs);
152                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
153                 traverse_commit_list(&revs, show_commit, show_object);
154                 exit(0);
155         }
156
157         if (pipe(pu_pipe) < 0)
158                 die("git-upload-pack: unable to create pipe");
159         if (pipe(pe_pipe) < 0)
160                 die("git-upload-pack: unable to create pipe");
161         pid_pack_objects = fork();
162         if (pid_pack_objects < 0) {
163                 /* daemon sets things up to ignore TERM */
164                 kill(pid_rev_list, SIGKILL);
165                 die("git-upload-pack: unable to fork git-pack-objects");
166         }
167         if (!pid_pack_objects) {
168                 const char *argv[10];
169                 int i = 0;
170
171                 dup2(lp_pipe[0], 0);
172                 dup2(pu_pipe[1], 1);
173                 dup2(pe_pipe[1], 2);
174
175                 close(lp_pipe[0]);
176                 close(lp_pipe[1]);
177                 close(pu_pipe[0]);
178                 close(pu_pipe[1]);
179                 close(pe_pipe[0]);
180                 close(pe_pipe[1]);
181
182                 argv[i++] = "pack-objects";
183                 argv[i++] = "--stdout";
184                 if (!no_progress)
185                         argv[i++] = "--progress";
186                 if (use_ofs_delta)
187                         argv[i++] = "--delta-base-offset";
188                 argv[i++] = NULL;
189
190                 execv_git_cmd(argv);
191                 kill(pid_rev_list, SIGKILL);
192                 die("git-upload-pack: unable to exec git-pack-objects");
193         }
194
195         close(lp_pipe[0]);
196         close(lp_pipe[1]);
197
198         /* We read from pe_pipe[0] to capture stderr output for
199          * progress bar, and pu_pipe[0] to capture the pack data.
200          */
201         close(pe_pipe[1]);
202         close(pu_pipe[1]);
203
204         while (1) {
205                 const char *who;
206                 struct pollfd pfd[2];
207                 pid_t pid;
208                 int status;
209                 ssize_t sz;
210                 int pe, pu, pollsize;
211
212                 reset_timeout();
213
214                 pollsize = 0;
215                 pe = pu = -1;
216
217                 if (0 <= pu_pipe[0]) {
218                         pfd[pollsize].fd = pu_pipe[0];
219                         pfd[pollsize].events = POLLIN;
220                         pu = pollsize;
221                         pollsize++;
222                 }
223                 if (0 <= pe_pipe[0]) {
224                         pfd[pollsize].fd = pe_pipe[0];
225                         pfd[pollsize].events = POLLIN;
226                         pe = pollsize;
227                         pollsize++;
228                 }
229
230                 if (pollsize) {
231                         if (poll(pfd, pollsize, -1) < 0) {
232                                 if (errno != EINTR) {
233                                         error("poll failed, resuming: %s",
234                                               strerror(errno));
235                                         sleep(1);
236                                 }
237                                 continue;
238                         }
239                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
240                                 /* Data ready; we keep the last byte
241                                  * to ourselves in case we detect
242                                  * broken rev-list, so that we can
243                                  * leave the stream corrupted.  This
244                                  * is unfortunate -- unpack-objects
245                                  * would happily accept a valid pack
246                                  * data with trailing garbage, so
247                                  * appending garbage after we pass all
248                                  * the pack data is not good enough to
249                                  * signal breakage to downstream.
250                                  */
251                                 char *cp = data;
252                                 ssize_t outsz = 0;
253                                 if (0 <= buffered) {
254                                         *cp++ = buffered;
255                                         outsz++;
256                                 }
257                                 sz = xread(pu_pipe[0], cp,
258                                           sizeof(data) - outsz);
259                                 if (0 < sz)
260                                                 ;
261                                 else if (sz == 0) {
262                                         close(pu_pipe[0]);
263                                         pu_pipe[0] = -1;
264                                 }
265                                 else
266                                         goto fail;
267                                 sz += outsz;
268                                 if (1 < sz) {
269                                         buffered = data[sz-1] & 0xFF;
270                                         sz--;
271                                 }
272                                 else
273                                         buffered = -1;
274                                 sz = send_client_data(1, data, sz);
275                                 if (sz < 0)
276                                         goto fail;
277                         }
278                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
279                                 /* Status ready; we ship that in the side-band
280                                  * or dump to the standard error.
281                                  */
282                                 sz = xread(pe_pipe[0], progress,
283                                           sizeof(progress));
284                                 if (0 < sz)
285                                         send_client_data(2, progress, sz);
286                                 else if (sz == 0) {
287                                         close(pe_pipe[0]);
288                                         pe_pipe[0] = -1;
289                                 }
290                                 else
291                                         goto fail;
292                         }
293                 }
294
295                 /* See if the children are still there */
296                 if (pid_rev_list || pid_pack_objects) {
297                         pid = waitpid(-1, &status, WNOHANG);
298                         if (!pid)
299                                 continue;
300                         who = ((pid == pid_rev_list) ? "git-rev-list" :
301                                (pid == pid_pack_objects) ? "git-pack-objects" :
302                                NULL);
303                         if (!who) {
304                                 if (pid < 0) {
305                                         error("git-upload-pack: %s",
306                                               strerror(errno));
307                                         goto fail;
308                                 }
309                                 error("git-upload-pack: we weren't "
310                                       "waiting for %d", pid);
311                                 continue;
312                         }
313                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
314                                 error("git-upload-pack: %s died with error.",
315                                       who);
316                                 goto fail;
317                         }
318                         if (pid == pid_rev_list)
319                                 pid_rev_list = 0;
320                         if (pid == pid_pack_objects)
321                                 pid_pack_objects = 0;
322                         if (pid_rev_list || pid_pack_objects)
323                                 continue;
324                 }
325
326                 /* both died happily */
327                 if (pollsize)
328                         continue;
329
330                 /* flush the data */
331                 if (0 <= buffered) {
332                         data[0] = buffered;
333                         sz = send_client_data(1, data, 1);
334                         if (sz < 0)
335                                 goto fail;
336                         fprintf(stderr, "flushed.\n");
337                 }
338                 if (use_sideband)
339                         packet_flush(1);
340                 return;
341         }
342  fail:
343         if (pid_pack_objects)
344                 kill(pid_pack_objects, SIGKILL);
345         if (pid_rev_list)
346                 kill(pid_rev_list, SIGKILL);
347         send_client_data(3, abort_msg, sizeof(abort_msg));
348         die("git-upload-pack: %s", abort_msg);
349 }
350
351 static int got_sha1(char *hex, unsigned char *sha1)
352 {
353         struct object *o;
354         int we_knew_they_have = 0;
355
356         if (get_sha1_hex(hex, sha1))
357                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
358         if (!has_sha1_file(sha1))
359                 return -1;
360
361         o = lookup_object(sha1);
362         if (!(o && o->parsed))
363                 o = parse_object(sha1);
364         if (!o)
365                 die("oops (%s)", sha1_to_hex(sha1));
366         if (o->type == OBJ_COMMIT) {
367                 struct commit_list *parents;
368                 struct commit *commit = (struct commit *)o;
369                 if (o->flags & THEY_HAVE)
370                         we_knew_they_have = 1;
371                 else
372                         o->flags |= THEY_HAVE;
373                 if (!oldest_have || (commit->date < oldest_have))
374                         oldest_have = commit->date;
375                 for (parents = commit->parents;
376                      parents;
377                      parents = parents->next)
378                         parents->item->object.flags |= THEY_HAVE;
379         }
380         if (!we_knew_they_have) {
381                 add_object_array(o, NULL, &have_obj);
382                 return 1;
383         }
384         return 0;
385 }
386
387 static int reachable(struct commit *want)
388 {
389         struct commit_list *work = NULL;
390
391         insert_by_date(want, &work);
392         while (work) {
393                 struct commit_list *list = work->next;
394                 struct commit *commit = work->item;
395                 free(work);
396                 work = list;
397
398                 if (commit->object.flags & THEY_HAVE) {
399                         want->object.flags |= COMMON_KNOWN;
400                         break;
401                 }
402                 if (!commit->object.parsed)
403                         parse_object(commit->object.sha1);
404                 if (commit->object.flags & REACHABLE)
405                         continue;
406                 commit->object.flags |= REACHABLE;
407                 if (commit->date < oldest_have)
408                         continue;
409                 for (list = commit->parents; list; list = list->next) {
410                         struct commit *parent = list->item;
411                         if (!(parent->object.flags & REACHABLE))
412                                 insert_by_date(parent, &work);
413                 }
414         }
415         want->object.flags |= REACHABLE;
416         clear_commit_marks(want, REACHABLE);
417         free_commit_list(work);
418         return (want->object.flags & COMMON_KNOWN);
419 }
420
421 static int ok_to_give_up(void)
422 {
423         int i;
424
425         if (!have_obj.nr)
426                 return 0;
427
428         for (i = 0; i < want_obj.nr; i++) {
429                 struct object *want = want_obj.objects[i].item;
430
431                 if (want->flags & COMMON_KNOWN)
432                         continue;
433                 want = deref_tag(want, "a want line", 0);
434                 if (!want || want->type != OBJ_COMMIT) {
435                         /* no way to tell if this is reachable by
436                          * looking at the ancestry chain alone, so
437                          * leave a note to ourselves not to worry about
438                          * this object anymore.
439                          */
440                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
441                         continue;
442                 }
443                 if (!reachable((struct commit *)want))
444                         return 0;
445         }
446         return 1;
447 }
448
449 static int get_common_commits(void)
450 {
451         static char line[1000];
452         unsigned char sha1[20];
453         char hex[41], last_hex[41];
454         int len;
455
456         track_object_refs = 0;
457         save_commit_buffer = 0;
458
459         for(;;) {
460                 len = packet_read_line(0, line, sizeof(line));
461                 reset_timeout();
462
463                 if (!len) {
464                         if (have_obj.nr == 0 || multi_ack)
465                                 packet_write(1, "NAK\n");
466                         continue;
467                 }
468                 len = strip(line, len);
469                 if (!prefixcmp(line, "have ")) {
470                         switch (got_sha1(line+5, sha1)) {
471                         case -1: /* they have what we do not */
472                                 if (multi_ack && ok_to_give_up())
473                                         packet_write(1, "ACK %s continue\n",
474                                                      sha1_to_hex(sha1));
475                                 break;
476                         default:
477                                 memcpy(hex, sha1_to_hex(sha1), 41);
478                                 if (multi_ack) {
479                                         const char *msg = "ACK %s continue\n";
480                                         packet_write(1, msg, hex);
481                                         memcpy(last_hex, hex, 41);
482                                 }
483                                 else if (have_obj.nr == 1)
484                                         packet_write(1, "ACK %s\n", hex);
485                                 break;
486                         }
487                         continue;
488                 }
489                 if (!strcmp(line, "done")) {
490                         if (have_obj.nr > 0) {
491                                 if (multi_ack)
492                                         packet_write(1, "ACK %s\n", last_hex);
493                                 return 0;
494                         }
495                         packet_write(1, "NAK\n");
496                         return -1;
497                 }
498                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
499         }
500 }
501
502 static void receive_needs(void)
503 {
504         struct object_array shallows = {0, 0, NULL};
505         static char line[1000];
506         int len, depth = 0;
507
508         for (;;) {
509                 struct object *o;
510                 unsigned char sha1_buf[20];
511                 len = packet_read_line(0, line, sizeof(line));
512                 reset_timeout();
513                 if (!len)
514                         break;
515
516                 if (!prefixcmp(line, "shallow ")) {
517                         unsigned char sha1[20];
518                         struct object *object;
519                         use_thin_pack = 0;
520                         if (get_sha1(line + 8, sha1))
521                                 die("invalid shallow line: %s", line);
522                         object = parse_object(sha1);
523                         if (!object)
524                                 die("did not find object for %s", line);
525                         object->flags |= CLIENT_SHALLOW;
526                         add_object_array(object, NULL, &shallows);
527                         continue;
528                 }
529                 if (!prefixcmp(line, "deepen ")) {
530                         char *end;
531                         use_thin_pack = 0;
532                         depth = strtol(line + 7, &end, 0);
533                         if (end == line + 7 || depth <= 0)
534                                 die("Invalid deepen: %s", line);
535                         continue;
536                 }
537                 if (prefixcmp(line, "want ") ||
538                     get_sha1_hex(line+5, sha1_buf))
539                         die("git-upload-pack: protocol error, "
540                             "expected to get sha, not '%s'", line);
541                 if (strstr(line+45, "multi_ack"))
542                         multi_ack = 1;
543                 if (strstr(line+45, "thin-pack"))
544                         use_thin_pack = 1;
545                 if (strstr(line+45, "ofs-delta"))
546                         use_ofs_delta = 1;
547                 if (strstr(line+45, "side-band-64k"))
548                         use_sideband = LARGE_PACKET_MAX;
549                 else if (strstr(line+45, "side-band"))
550                         use_sideband = DEFAULT_PACKET_MAX;
551                 if (strstr(line+45, "no-progress"))
552                         no_progress = 1;
553
554                 /* We have sent all our refs already, and the other end
555                  * should have chosen out of them; otherwise they are
556                  * asking for nonsense.
557                  *
558                  * Hmph.  We may later want to allow "want" line that
559                  * asks for something like "master~10" (symbolic)...
560                  * would it make sense?  I don't know.
561                  */
562                 o = lookup_object(sha1_buf);
563                 if (!o || !(o->flags & OUR_REF))
564                         die("git-upload-pack: not our ref %s", line+5);
565                 if (!(o->flags & WANTED)) {
566                         o->flags |= WANTED;
567                         add_object_array(o, NULL, &want_obj);
568                 }
569         }
570         if (depth == 0 && shallows.nr == 0)
571                 return;
572         if (depth > 0) {
573                 struct commit_list *result, *backup;
574                 int i;
575                 backup = result = get_shallow_commits(&want_obj, depth,
576                         SHALLOW, NOT_SHALLOW);
577                 while (result) {
578                         struct object *object = &result->item->object;
579                         if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
580                                 packet_write(1, "shallow %s",
581                                                 sha1_to_hex(object->sha1));
582                                 register_shallow(object->sha1);
583                         }
584                         result = result->next;
585                 }
586                 free_commit_list(backup);
587                 for (i = 0; i < shallows.nr; i++) {
588                         struct object *object = shallows.objects[i].item;
589                         if (object->flags & NOT_SHALLOW) {
590                                 struct commit_list *parents;
591                                 packet_write(1, "unshallow %s",
592                                         sha1_to_hex(object->sha1));
593                                 object->flags &= ~CLIENT_SHALLOW;
594                                 /* make sure the real parents are parsed */
595                                 unregister_shallow(object->sha1);
596                                 object->parsed = 0;
597                                 parse_commit((struct commit *)object);
598                                 parents = ((struct commit *)object)->parents;
599                                 while (parents) {
600                                         add_object_array(&parents->item->object,
601                                                         NULL, &want_obj);
602                                         parents = parents->next;
603                                 }
604                         }
605                         /* make sure commit traversal conforms to client */
606                         register_shallow(object->sha1);
607                 }
608                 packet_flush(1);
609         } else
610                 if (shallows.nr > 0) {
611                         int i;
612                         for (i = 0; i < shallows.nr; i++)
613                                 register_shallow(shallows.objects[i].item->sha1);
614                 }
615         free(shallows.objects);
616 }
617
618 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
619 {
620         static const char *capabilities = "multi_ack thin-pack side-band"
621                 " side-band-64k ofs-delta shallow no-progress";
622         struct object *o = parse_object(sha1);
623
624         if (!o)
625                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
626
627         if (capabilities)
628                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
629                         0, capabilities);
630         else
631                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
632         capabilities = NULL;
633         if (!(o->flags & OUR_REF)) {
634                 o->flags |= OUR_REF;
635                 nr_our_refs++;
636         }
637         if (o->type == OBJ_TAG) {
638                 o = deref_tag(o, refname, 0);
639                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
640         }
641         return 0;
642 }
643
644 static void upload_pack(void)
645 {
646         reset_timeout();
647         head_ref(send_ref, NULL);
648         for_each_ref(send_ref, NULL);
649         packet_flush(1);
650         receive_needs();
651         if (want_obj.nr) {
652                 get_common_commits();
653                 create_pack_file();
654         }
655 }
656
657 int main(int argc, char **argv)
658 {
659         char *dir;
660         int i;
661         int strict = 0;
662
663         for (i = 1; i < argc; i++) {
664                 char *arg = argv[i];
665
666                 if (arg[0] != '-')
667                         break;
668                 if (!strcmp(arg, "--strict")) {
669                         strict = 1;
670                         continue;
671                 }
672                 if (!prefixcmp(arg, "--timeout=")) {
673                         timeout = atoi(arg+10);
674                         continue;
675                 }
676                 if (!strcmp(arg, "--")) {
677                         i++;
678                         break;
679                 }
680         }
681
682         if (i != argc-1)
683                 usage(upload_pack_usage);
684         dir = argv[i];
685
686         if (!enter_repo(dir, strict))
687                 die("'%s': unable to chdir or not a git archive", dir);
688         if (is_repository_shallow())
689                 die("attempt to fetch/clone from a shallow repository");
690         upload_pack();
691         return 0;
692 }