fast-import: checkpoint: dump branches/tags/marks even if object_count==0
[git] / send-pack.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "commit.h"
4 #include "refs.h"
5 #include "pkt-line.h"
6 #include "sideband.h"
7 #include "run-command.h"
8 #include "remote.h"
9 #include "connect.h"
10 #include "send-pack.h"
11 #include "quote.h"
12 #include "transport.h"
13 #include "version.h"
14 #include "sha1-array.h"
15 #include "gpg-interface.h"
16 #include "cache.h"
17
18 int option_parse_push_signed(const struct option *opt,
19                              const char *arg, int unset)
20 {
21         if (unset) {
22                 *(int *)(opt->value) = SEND_PACK_PUSH_CERT_NEVER;
23                 return 0;
24         }
25         switch (git_parse_maybe_bool(arg)) {
26         case 1:
27                 *(int *)(opt->value) = SEND_PACK_PUSH_CERT_ALWAYS;
28                 return 0;
29         case 0:
30                 *(int *)(opt->value) = SEND_PACK_PUSH_CERT_NEVER;
31                 return 0;
32         }
33         if (!strcasecmp("if-asked", arg)) {
34                 *(int *)(opt->value) = SEND_PACK_PUSH_CERT_IF_ASKED;
35                 return 0;
36         }
37         die("bad %s argument: %s", opt->long_name, arg);
38 }
39
40 static void feed_object(const unsigned char *sha1, FILE *fh, int negative)
41 {
42         if (negative && !has_sha1_file(sha1))
43                 return;
44
45         if (negative)
46                 putc('^', fh);
47         fputs(sha1_to_hex(sha1), fh);
48         putc('\n', fh);
49 }
50
51 /*
52  * Make a pack stream and spit it out into file descriptor fd
53  */
54 static int pack_objects(int fd, struct ref *refs, struct oid_array *extra, struct send_pack_args *args)
55 {
56         /*
57          * The child becomes pack-objects --revs; we feed
58          * the revision parameters to it via its stdin and
59          * let its stdout go back to the other end.
60          */
61         const char *argv[] = {
62                 "pack-objects",
63                 "--all-progress-implied",
64                 "--revs",
65                 "--stdout",
66                 NULL,
67                 NULL,
68                 NULL,
69                 NULL,
70                 NULL,
71                 NULL,
72         };
73         struct child_process po = CHILD_PROCESS_INIT;
74         FILE *po_in;
75         int i;
76         int rc;
77
78         i = 4;
79         if (args->use_thin_pack)
80                 argv[i++] = "--thin";
81         if (args->use_ofs_delta)
82                 argv[i++] = "--delta-base-offset";
83         if (args->quiet || !args->progress)
84                 argv[i++] = "-q";
85         if (args->progress)
86                 argv[i++] = "--progress";
87         if (is_repository_shallow())
88                 argv[i++] = "--shallow";
89         po.argv = argv;
90         po.in = -1;
91         po.out = args->stateless_rpc ? -1 : fd;
92         po.git_cmd = 1;
93         if (start_command(&po))
94                 die_errno("git pack-objects failed");
95
96         /*
97          * We feed the pack-objects we just spawned with revision
98          * parameters by writing to the pipe.
99          */
100         po_in = xfdopen(po.in, "w");
101         for (i = 0; i < extra->nr; i++)
102                 feed_object(extra->oid[i].hash, po_in, 1);
103
104         while (refs) {
105                 if (!is_null_oid(&refs->old_oid))
106                         feed_object(refs->old_oid.hash, po_in, 1);
107                 if (!is_null_oid(&refs->new_oid))
108                         feed_object(refs->new_oid.hash, po_in, 0);
109                 refs = refs->next;
110         }
111
112         fflush(po_in);
113         if (ferror(po_in))
114                 die_errno("error writing to pack-objects");
115         fclose(po_in);
116
117         if (args->stateless_rpc) {
118                 char *buf = xmalloc(LARGE_PACKET_MAX);
119                 while (1) {
120                         ssize_t n = xread(po.out, buf, LARGE_PACKET_MAX);
121                         if (n <= 0)
122                                 break;
123                         send_sideband(fd, -1, buf, n, LARGE_PACKET_MAX);
124                 }
125                 free(buf);
126                 close(po.out);
127                 po.out = -1;
128         }
129
130         rc = finish_command(&po);
131         if (rc) {
132                 /*
133                  * For a normal non-zero exit, we assume pack-objects wrote
134                  * something useful to stderr. For death by signal, though,
135                  * we should mention it to the user. The exception is SIGPIPE
136                  * (141), because that's a normal occurrence if the remote end
137                  * hangs up (and we'll report that by trying to read the unpack
138                  * status).
139                  */
140                 if (rc > 128 && rc != 141)
141                         error("pack-objects died of signal %d", rc - 128);
142                 return -1;
143         }
144         return 0;
145 }
146
147 static int receive_unpack_status(int in)
148 {
149         const char *line = packet_read_line(in, NULL);
150         if (!skip_prefix(line, "unpack ", &line))
151                 return error(_("unable to parse remote unpack status: %s"), line);
152         if (strcmp(line, "ok"))
153                 return error(_("remote unpack failed: %s"), line);
154         return 0;
155 }
156
157 static int receive_status(int in, struct ref *refs)
158 {
159         struct ref *hint;
160         int ret;
161
162         hint = NULL;
163         ret = receive_unpack_status(in);
164         while (1) {
165                 char *refname;
166                 char *msg;
167                 char *line = packet_read_line(in, NULL);
168                 if (!line)
169                         break;
170                 if (!starts_with(line, "ok ") && !starts_with(line, "ng ")) {
171                         error("invalid ref status from remote: %s", line);
172                         ret = -1;
173                         break;
174                 }
175
176                 refname = line + 3;
177                 msg = strchr(refname, ' ');
178                 if (msg)
179                         *msg++ = '\0';
180
181                 /* first try searching at our hint, falling back to all refs */
182                 if (hint)
183                         hint = find_ref_by_name(hint, refname);
184                 if (!hint)
185                         hint = find_ref_by_name(refs, refname);
186                 if (!hint) {
187                         warning("remote reported status on unknown ref: %s",
188                                         refname);
189                         continue;
190                 }
191                 if (hint->status != REF_STATUS_EXPECTING_REPORT) {
192                         warning("remote reported status on unexpected ref: %s",
193                                         refname);
194                         continue;
195                 }
196
197                 if (line[0] == 'o' && line[1] == 'k')
198                         hint->status = REF_STATUS_OK;
199                 else {
200                         hint->status = REF_STATUS_REMOTE_REJECT;
201                         ret = -1;
202                 }
203                 hint->remote_status = xstrdup_or_null(msg);
204                 /* start our next search from the next ref */
205                 hint = hint->next;
206         }
207         return ret;
208 }
209
210 static int sideband_demux(int in, int out, void *data)
211 {
212         int *fd = data, ret;
213 #ifdef NO_PTHREADS
214         close(fd[1]);
215 #endif
216         ret = recv_sideband("send-pack", fd[0], out);
217         close(out);
218         return ret;
219 }
220
221 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
222 {
223         struct strbuf *sb = cb;
224         if (graft->nr_parent == -1)
225                 packet_buf_write(sb, "shallow %s\n", oid_to_hex(&graft->oid));
226         return 0;
227 }
228
229 static void advertise_shallow_grafts_buf(struct strbuf *sb)
230 {
231         if (!is_repository_shallow())
232                 return;
233         for_each_commit_graft(advertise_shallow_grafts_cb, sb);
234 }
235
236 #define CHECK_REF_NO_PUSH -1
237 #define CHECK_REF_STATUS_REJECTED -2
238 #define CHECK_REF_UPTODATE -3
239 static int check_to_send_update(const struct ref *ref, const struct send_pack_args *args)
240 {
241         if (!ref->peer_ref && !args->send_mirror)
242                 return CHECK_REF_NO_PUSH;
243
244         /* Check for statuses set by set_ref_status_for_push() */
245         switch (ref->status) {
246         case REF_STATUS_REJECT_NONFASTFORWARD:
247         case REF_STATUS_REJECT_ALREADY_EXISTS:
248         case REF_STATUS_REJECT_FETCH_FIRST:
249         case REF_STATUS_REJECT_NEEDS_FORCE:
250         case REF_STATUS_REJECT_STALE:
251         case REF_STATUS_REJECT_NODELETE:
252                 return CHECK_REF_STATUS_REJECTED;
253         case REF_STATUS_UPTODATE:
254                 return CHECK_REF_UPTODATE;
255         default:
256                 return 0;
257         }
258 }
259
260 /*
261  * the beginning of the next line, or the end of buffer.
262  *
263  * NEEDSWORK: perhaps move this to git-compat-util.h or somewhere and
264  * convert many similar uses found by "git grep -A4 memchr".
265  */
266 static const char *next_line(const char *line, size_t len)
267 {
268         const char *nl = memchr(line, '\n', len);
269         if (!nl)
270                 return line + len; /* incomplete line */
271         return nl + 1;
272 }
273
274 static int generate_push_cert(struct strbuf *req_buf,
275                               const struct ref *remote_refs,
276                               struct send_pack_args *args,
277                               const char *cap_string,
278                               const char *push_cert_nonce)
279 {
280         const struct ref *ref;
281         struct string_list_item *item;
282         char *signing_key = xstrdup(get_signing_key());
283         const char *cp, *np;
284         struct strbuf cert = STRBUF_INIT;
285         int update_seen = 0;
286
287         strbuf_addstr(&cert, "certificate version 0.1\n");
288         strbuf_addf(&cert, "pusher %s ", signing_key);
289         datestamp(&cert);
290         strbuf_addch(&cert, '\n');
291         if (args->url && *args->url) {
292                 char *anon_url = transport_anonymize_url(args->url);
293                 strbuf_addf(&cert, "pushee %s\n", anon_url);
294                 free(anon_url);
295         }
296         if (push_cert_nonce[0])
297                 strbuf_addf(&cert, "nonce %s\n", push_cert_nonce);
298         if (args->push_options)
299                 for_each_string_list_item(item, args->push_options)
300                         strbuf_addf(&cert, "push-option %s\n", item->string);
301         strbuf_addstr(&cert, "\n");
302
303         for (ref = remote_refs; ref; ref = ref->next) {
304                 if (check_to_send_update(ref, args) < 0)
305                         continue;
306                 update_seen = 1;
307                 strbuf_addf(&cert, "%s %s %s\n",
308                             oid_to_hex(&ref->old_oid),
309                             oid_to_hex(&ref->new_oid),
310                             ref->name);
311         }
312         if (!update_seen)
313                 goto free_return;
314
315         if (sign_buffer(&cert, &cert, signing_key))
316                 die(_("failed to sign the push certificate"));
317
318         packet_buf_write(req_buf, "push-cert%c%s", 0, cap_string);
319         for (cp = cert.buf; cp < cert.buf + cert.len; cp = np) {
320                 np = next_line(cp, cert.buf + cert.len - cp);
321                 packet_buf_write(req_buf,
322                                  "%.*s", (int)(np - cp), cp);
323         }
324         packet_buf_write(req_buf, "push-cert-end\n");
325
326 free_return:
327         free(signing_key);
328         strbuf_release(&cert);
329         return update_seen;
330 }
331
332
333 static int atomic_push_failure(struct send_pack_args *args,
334                                struct ref *remote_refs,
335                                struct ref *failing_ref)
336 {
337         struct ref *ref;
338         /* Mark other refs as failed */
339         for (ref = remote_refs; ref; ref = ref->next) {
340                 if (!ref->peer_ref && !args->send_mirror)
341                         continue;
342
343                 switch (ref->status) {
344                 case REF_STATUS_EXPECTING_REPORT:
345                         ref->status = REF_STATUS_ATOMIC_PUSH_FAILED;
346                         continue;
347                 default:
348                         break; /* do nothing */
349                 }
350         }
351         return error("atomic push failed for ref %s. status: %d\n",
352                      failing_ref->name, failing_ref->status);
353 }
354
355 #define NONCE_LEN_LIMIT 256
356
357 static void reject_invalid_nonce(const char *nonce, int len)
358 {
359         int i = 0;
360
361         if (NONCE_LEN_LIMIT <= len)
362                 die("the receiving end asked to sign an invalid nonce <%.*s>",
363                     len, nonce);
364
365         for (i = 0; i < len; i++) {
366                 int ch = nonce[i] & 0xFF;
367                 if (isalnum(ch) ||
368                     ch == '-' || ch == '.' ||
369                     ch == '/' || ch == '+' ||
370                     ch == '=' || ch == '_')
371                         continue;
372                 die("the receiving end asked to sign an invalid nonce <%.*s>",
373                     len, nonce);
374         }
375 }
376
377 int send_pack(struct send_pack_args *args,
378               int fd[], struct child_process *conn,
379               struct ref *remote_refs,
380               struct oid_array *extra_have)
381 {
382         int in = fd[0];
383         int out = fd[1];
384         struct strbuf req_buf = STRBUF_INIT;
385         struct strbuf cap_buf = STRBUF_INIT;
386         struct ref *ref;
387         int need_pack_data = 0;
388         int allow_deleting_refs = 0;
389         int status_report = 0;
390         int use_sideband = 0;
391         int quiet_supported = 0;
392         int agent_supported = 0;
393         int use_atomic = 0;
394         int atomic_supported = 0;
395         int use_push_options = 0;
396         int push_options_supported = 0;
397         unsigned cmds_sent = 0;
398         int ret;
399         struct async demux;
400         const char *push_cert_nonce = NULL;
401
402         /* Does the other end support the reporting? */
403         if (server_supports("report-status"))
404                 status_report = 1;
405         if (server_supports("delete-refs"))
406                 allow_deleting_refs = 1;
407         if (server_supports("ofs-delta"))
408                 args->use_ofs_delta = 1;
409         if (server_supports("side-band-64k"))
410                 use_sideband = 1;
411         if (server_supports("quiet"))
412                 quiet_supported = 1;
413         if (server_supports("agent"))
414                 agent_supported = 1;
415         if (server_supports("no-thin"))
416                 args->use_thin_pack = 0;
417         if (server_supports("atomic"))
418                 atomic_supported = 1;
419         if (server_supports("push-options"))
420                 push_options_supported = 1;
421
422         if (args->push_cert != SEND_PACK_PUSH_CERT_NEVER) {
423                 int len;
424                 push_cert_nonce = server_feature_value("push-cert", &len);
425                 if (push_cert_nonce) {
426                         reject_invalid_nonce(push_cert_nonce, len);
427                         push_cert_nonce = xmemdupz(push_cert_nonce, len);
428                 } else if (args->push_cert == SEND_PACK_PUSH_CERT_ALWAYS) {
429                         die(_("the receiving end does not support --signed push"));
430                 } else if (args->push_cert == SEND_PACK_PUSH_CERT_IF_ASKED) {
431                         warning(_("not sending a push certificate since the"
432                                   " receiving end does not support --signed"
433                                   " push"));
434                 }
435         }
436
437         if (!remote_refs) {
438                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
439                         "Perhaps you should specify a branch such as 'master'.\n");
440                 return 0;
441         }
442         if (args->atomic && !atomic_supported)
443                 die(_("the receiving end does not support --atomic push"));
444
445         use_atomic = atomic_supported && args->atomic;
446
447         if (args->push_options && !push_options_supported)
448                 die(_("the receiving end does not support push options"));
449
450         use_push_options = push_options_supported && args->push_options;
451
452         if (status_report)
453                 strbuf_addstr(&cap_buf, " report-status");
454         if (use_sideband)
455                 strbuf_addstr(&cap_buf, " side-band-64k");
456         if (quiet_supported && (args->quiet || !args->progress))
457                 strbuf_addstr(&cap_buf, " quiet");
458         if (use_atomic)
459                 strbuf_addstr(&cap_buf, " atomic");
460         if (use_push_options)
461                 strbuf_addstr(&cap_buf, " push-options");
462         if (agent_supported)
463                 strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());
464
465         /*
466          * NEEDSWORK: why does delete-refs have to be so specific to
467          * send-pack machinery that set_ref_status_for_push() cannot
468          * set this bit for us???
469          */
470         for (ref = remote_refs; ref; ref = ref->next)
471                 if (ref->deletion && !allow_deleting_refs)
472                         ref->status = REF_STATUS_REJECT_NODELETE;
473
474         if (!args->dry_run)
475                 advertise_shallow_grafts_buf(&req_buf);
476
477         if (!args->dry_run && push_cert_nonce)
478                 cmds_sent = generate_push_cert(&req_buf, remote_refs, args,
479                                                cap_buf.buf, push_cert_nonce);
480
481         /*
482          * Clear the status for each ref and see if we need to send
483          * the pack data.
484          */
485         for (ref = remote_refs; ref; ref = ref->next) {
486                 switch (check_to_send_update(ref, args)) {
487                 case 0: /* no error */
488                         break;
489                 case CHECK_REF_STATUS_REJECTED:
490                         /*
491                          * When we know the server would reject a ref update if
492                          * we were to send it and we're trying to send the refs
493                          * atomically, abort the whole operation.
494                          */
495                         if (use_atomic)
496                                 return atomic_push_failure(args, remote_refs, ref);
497                         /* Fallthrough for non atomic case. */
498                 default:
499                         continue;
500                 }
501                 if (!ref->deletion)
502                         need_pack_data = 1;
503
504                 if (args->dry_run || !status_report)
505                         ref->status = REF_STATUS_OK;
506                 else
507                         ref->status = REF_STATUS_EXPECTING_REPORT;
508         }
509
510         /*
511          * Finally, tell the other end!
512          */
513         for (ref = remote_refs; ref; ref = ref->next) {
514                 char *old_hex, *new_hex;
515
516                 if (args->dry_run || push_cert_nonce)
517                         continue;
518
519                 if (check_to_send_update(ref, args) < 0)
520                         continue;
521
522                 old_hex = oid_to_hex(&ref->old_oid);
523                 new_hex = oid_to_hex(&ref->new_oid);
524                 if (!cmds_sent) {
525                         packet_buf_write(&req_buf,
526                                          "%s %s %s%c%s",
527                                          old_hex, new_hex, ref->name, 0,
528                                          cap_buf.buf);
529                         cmds_sent = 1;
530                 } else {
531                         packet_buf_write(&req_buf, "%s %s %s",
532                                          old_hex, new_hex, ref->name);
533                 }
534         }
535
536         if (use_push_options) {
537                 struct string_list_item *item;
538
539                 packet_buf_flush(&req_buf);
540                 for_each_string_list_item(item, args->push_options)
541                         packet_buf_write(&req_buf, "%s", item->string);
542         }
543
544         if (args->stateless_rpc) {
545                 if (!args->dry_run && (cmds_sent || is_repository_shallow())) {
546                         packet_buf_flush(&req_buf);
547                         send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
548                 }
549         } else {
550                 write_or_die(out, req_buf.buf, req_buf.len);
551                 packet_flush(out);
552         }
553         strbuf_release(&req_buf);
554         strbuf_release(&cap_buf);
555
556         if (use_sideband && cmds_sent) {
557                 memset(&demux, 0, sizeof(demux));
558                 demux.proc = sideband_demux;
559                 demux.data = fd;
560                 demux.out = -1;
561                 demux.isolate_sigpipe = 1;
562                 if (start_async(&demux))
563                         die("send-pack: unable to fork off sideband demultiplexer");
564                 in = demux.out;
565         }
566
567         if (need_pack_data && cmds_sent) {
568                 if (pack_objects(out, remote_refs, extra_have, args) < 0) {
569                         for (ref = remote_refs; ref; ref = ref->next)
570                                 ref->status = REF_STATUS_NONE;
571                         if (args->stateless_rpc)
572                                 close(out);
573                         if (git_connection_is_socket(conn))
574                                 shutdown(fd[0], SHUT_WR);
575
576                         /*
577                          * Do not even bother with the return value; we know we
578                          * are failing, and just want the error() side effects.
579                          */
580                         if (status_report)
581                                 receive_unpack_status(in);
582
583                         if (use_sideband) {
584                                 close(demux.out);
585                                 finish_async(&demux);
586                         }
587                         fd[1] = -1;
588                         return -1;
589                 }
590                 if (!args->stateless_rpc)
591                         /* Closed by pack_objects() via start_command() */
592                         fd[1] = -1;
593         }
594         if (args->stateless_rpc && cmds_sent)
595                 packet_flush(out);
596
597         if (status_report && cmds_sent)
598                 ret = receive_status(in, remote_refs);
599         else
600                 ret = 0;
601         if (args->stateless_rpc)
602                 packet_flush(out);
603
604         if (use_sideband && cmds_sent) {
605                 close(demux.out);
606                 if (finish_async(&demux)) {
607                         error("error in sideband demultiplexer");
608                         ret = -1;
609                 }
610         }
611
612         if (ret < 0)
613                 return ret;
614
615         if (args->porcelain)
616                 return 0;
617
618         for (ref = remote_refs; ref; ref = ref->next) {
619                 switch (ref->status) {
620                 case REF_STATUS_NONE:
621                 case REF_STATUS_UPTODATE:
622                 case REF_STATUS_OK:
623                         break;
624                 default:
625                         return -1;
626                 }
627         }
628         return 0;
629 }