send-pack: advertise session ID in capabilities
[git] / send-pack.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "commit.h"
4 #include "refs.h"
5 #include "object-store.h"
6 #include "pkt-line.h"
7 #include "sideband.h"
8 #include "run-command.h"
9 #include "remote.h"
10 #include "connect.h"
11 #include "send-pack.h"
12 #include "quote.h"
13 #include "transport.h"
14 #include "version.h"
15 #include "oid-array.h"
16 #include "gpg-interface.h"
17 #include "cache.h"
18 #include "shallow.h"
19
20 int option_parse_push_signed(const struct option *opt,
21                              const char *arg, int unset)
22 {
23         if (unset) {
24                 *(int *)(opt->value) = SEND_PACK_PUSH_CERT_NEVER;
25                 return 0;
26         }
27         switch (git_parse_maybe_bool(arg)) {
28         case 1:
29                 *(int *)(opt->value) = SEND_PACK_PUSH_CERT_ALWAYS;
30                 return 0;
31         case 0:
32                 *(int *)(opt->value) = SEND_PACK_PUSH_CERT_NEVER;
33                 return 0;
34         }
35         if (!strcasecmp("if-asked", arg)) {
36                 *(int *)(opt->value) = SEND_PACK_PUSH_CERT_IF_ASKED;
37                 return 0;
38         }
39         die("bad %s argument: %s", opt->long_name, arg);
40 }
41
42 static void feed_object(const struct object_id *oid, FILE *fh, int negative)
43 {
44         if (negative &&
45             !has_object_file_with_flags(oid,
46                                         OBJECT_INFO_SKIP_FETCH_OBJECT |
47                                         OBJECT_INFO_QUICK))
48                 return;
49
50         if (negative)
51                 putc('^', fh);
52         fputs(oid_to_hex(oid), fh);
53         putc('\n', fh);
54 }
55
56 /*
57  * Make a pack stream and spit it out into file descriptor fd
58  */
59 static int pack_objects(int fd, struct ref *refs, struct oid_array *extra, struct send_pack_args *args)
60 {
61         /*
62          * The child becomes pack-objects --revs; we feed
63          * the revision parameters to it via its stdin and
64          * let its stdout go back to the other end.
65          */
66         struct child_process po = CHILD_PROCESS_INIT;
67         FILE *po_in;
68         int i;
69         int rc;
70
71         strvec_push(&po.args, "pack-objects");
72         strvec_push(&po.args, "--all-progress-implied");
73         strvec_push(&po.args, "--revs");
74         strvec_push(&po.args, "--stdout");
75         if (args->use_thin_pack)
76                 strvec_push(&po.args, "--thin");
77         if (args->use_ofs_delta)
78                 strvec_push(&po.args, "--delta-base-offset");
79         if (args->quiet || !args->progress)
80                 strvec_push(&po.args, "-q");
81         if (args->progress)
82                 strvec_push(&po.args, "--progress");
83         if (is_repository_shallow(the_repository))
84                 strvec_push(&po.args, "--shallow");
85         po.in = -1;
86         po.out = args->stateless_rpc ? -1 : fd;
87         po.git_cmd = 1;
88         if (start_command(&po))
89                 die_errno("git pack-objects failed");
90
91         /*
92          * We feed the pack-objects we just spawned with revision
93          * parameters by writing to the pipe.
94          */
95         po_in = xfdopen(po.in, "w");
96         for (i = 0; i < extra->nr; i++)
97                 feed_object(&extra->oid[i], po_in, 1);
98
99         while (refs) {
100                 if (!is_null_oid(&refs->old_oid))
101                         feed_object(&refs->old_oid, po_in, 1);
102                 if (!is_null_oid(&refs->new_oid))
103                         feed_object(&refs->new_oid, po_in, 0);
104                 refs = refs->next;
105         }
106
107         fflush(po_in);
108         if (ferror(po_in))
109                 die_errno("error writing to pack-objects");
110         fclose(po_in);
111
112         if (args->stateless_rpc) {
113                 char *buf = xmalloc(LARGE_PACKET_MAX);
114                 while (1) {
115                         ssize_t n = xread(po.out, buf, LARGE_PACKET_MAX);
116                         if (n <= 0)
117                                 break;
118                         send_sideband(fd, -1, buf, n, LARGE_PACKET_MAX);
119                 }
120                 free(buf);
121                 close(po.out);
122                 po.out = -1;
123         }
124
125         rc = finish_command(&po);
126         if (rc) {
127                 /*
128                  * For a normal non-zero exit, we assume pack-objects wrote
129                  * something useful to stderr. For death by signal, though,
130                  * we should mention it to the user. The exception is SIGPIPE
131                  * (141), because that's a normal occurrence if the remote end
132                  * hangs up (and we'll report that by trying to read the unpack
133                  * status).
134                  */
135                 if (rc > 128 && rc != 141)
136                         error("pack-objects died of signal %d", rc - 128);
137                 return -1;
138         }
139         return 0;
140 }
141
142 static int receive_unpack_status(struct packet_reader *reader)
143 {
144         if (packet_reader_read(reader) != PACKET_READ_NORMAL)
145                 return error(_("unexpected flush packet while reading remote unpack status"));
146         if (!skip_prefix(reader->line, "unpack ", &reader->line))
147                 return error(_("unable to parse remote unpack status: %s"), reader->line);
148         if (strcmp(reader->line, "ok"))
149                 return error(_("remote unpack failed: %s"), reader->line);
150         return 0;
151 }
152
153 static int receive_status(struct packet_reader *reader, struct ref *refs)
154 {
155         struct ref *hint;
156         int ret;
157         struct ref_push_report *report = NULL;
158         int new_report = 0;
159         int once = 0;
160
161         hint = NULL;
162         ret = receive_unpack_status(reader);
163         while (1) {
164                 struct object_id old_oid, new_oid;
165                 const char *head;
166                 const char *refname;
167                 char *p;
168                 if (packet_reader_read(reader) != PACKET_READ_NORMAL)
169                         break;
170                 head = reader->line;
171                 p = strchr(head, ' ');
172                 if (!p) {
173                         error("invalid status line from remote: %s", reader->line);
174                         ret = -1;
175                         break;
176                 }
177                 *p++ = '\0';
178
179                 if (!strcmp(head, "option")) {
180                         const char *key, *val;
181
182                         if (!hint || !(report || new_report)) {
183                                 if (!once++)
184                                         error("'option' without a matching 'ok/ng' directive");
185                                 ret = -1;
186                                 continue;
187                         }
188                         if (new_report) {
189                                 if (!hint->report) {
190                                         hint->report = xcalloc(1, sizeof(struct ref_push_report));
191                                         report = hint->report;
192                                 } else {
193                                         report = hint->report;
194                                         while (report->next)
195                                                 report = report->next;
196                                         report->next = xcalloc(1, sizeof(struct ref_push_report));
197                                         report = report->next;
198                                 }
199                                 new_report = 0;
200                         }
201                         key = p;
202                         p = strchr(key, ' ');
203                         if (p)
204                                 *p++ = '\0';
205                         val = p;
206                         if (!strcmp(key, "refname"))
207                                 report->ref_name = xstrdup_or_null(val);
208                         else if (!strcmp(key, "old-oid") && val &&
209                                  !parse_oid_hex(val, &old_oid, &val))
210                                 report->old_oid = oiddup(&old_oid);
211                         else if (!strcmp(key, "new-oid") && val &&
212                                  !parse_oid_hex(val, &new_oid, &val))
213                                 report->new_oid = oiddup(&new_oid);
214                         else if (!strcmp(key, "forced-update"))
215                                 report->forced_update = 1;
216                         continue;
217                 }
218
219                 report = NULL;
220                 new_report = 0;
221                 if (strcmp(head, "ok") && strcmp(head, "ng")) {
222                         error("invalid ref status from remote: %s", head);
223                         ret = -1;
224                         break;
225                 }
226                 refname = p;
227                 p = strchr(refname, ' ');
228                 if (p)
229                         *p++ = '\0';
230                 /* first try searching at our hint, falling back to all refs */
231                 if (hint)
232                         hint = find_ref_by_name(hint, refname);
233                 if (!hint)
234                         hint = find_ref_by_name(refs, refname);
235                 if (!hint) {
236                         warning("remote reported status on unknown ref: %s",
237                                 refname);
238                         continue;
239                 }
240                 if (hint->status != REF_STATUS_EXPECTING_REPORT &&
241                     hint->status != REF_STATUS_OK &&
242                     hint->status != REF_STATUS_REMOTE_REJECT) {
243                         warning("remote reported status on unexpected ref: %s",
244                                 refname);
245                         continue;
246                 }
247                 if (!strcmp(head, "ng")) {
248                         hint->status = REF_STATUS_REMOTE_REJECT;
249                         if (p)
250                                 hint->remote_status = xstrdup(p);
251                         else
252                                 hint->remote_status = "failed";
253                 } else {
254                         hint->status = REF_STATUS_OK;
255                         hint->remote_status = xstrdup_or_null(p);
256                         new_report = 1;
257                 }
258         }
259         return ret;
260 }
261
262 static int sideband_demux(int in, int out, void *data)
263 {
264         int *fd = data, ret;
265         if (async_with_fork())
266                 close(fd[1]);
267         ret = recv_sideband("send-pack", fd[0], out);
268         close(out);
269         return ret;
270 }
271
272 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
273 {
274         struct strbuf *sb = cb;
275         if (graft->nr_parent == -1)
276                 packet_buf_write(sb, "shallow %s\n", oid_to_hex(&graft->oid));
277         return 0;
278 }
279
280 static void advertise_shallow_grafts_buf(struct strbuf *sb)
281 {
282         if (!is_repository_shallow(the_repository))
283                 return;
284         for_each_commit_graft(advertise_shallow_grafts_cb, sb);
285 }
286
287 #define CHECK_REF_NO_PUSH -1
288 #define CHECK_REF_STATUS_REJECTED -2
289 #define CHECK_REF_UPTODATE -3
290 static int check_to_send_update(const struct ref *ref, const struct send_pack_args *args)
291 {
292         if (!ref->peer_ref && !args->send_mirror)
293                 return CHECK_REF_NO_PUSH;
294
295         /* Check for statuses set by set_ref_status_for_push() */
296         switch (ref->status) {
297         case REF_STATUS_REJECT_NONFASTFORWARD:
298         case REF_STATUS_REJECT_ALREADY_EXISTS:
299         case REF_STATUS_REJECT_FETCH_FIRST:
300         case REF_STATUS_REJECT_NEEDS_FORCE:
301         case REF_STATUS_REJECT_STALE:
302         case REF_STATUS_REJECT_REMOTE_UPDATED:
303         case REF_STATUS_REJECT_NODELETE:
304                 return CHECK_REF_STATUS_REJECTED;
305         case REF_STATUS_UPTODATE:
306                 return CHECK_REF_UPTODATE;
307
308         default:
309         case REF_STATUS_EXPECTING_REPORT:
310                 /* already passed checks on the local side */
311         case REF_STATUS_OK:
312                 /* of course this is OK */
313                 return 0;
314         }
315 }
316
317 /*
318  * the beginning of the next line, or the end of buffer.
319  *
320  * NEEDSWORK: perhaps move this to git-compat-util.h or somewhere and
321  * convert many similar uses found by "git grep -A4 memchr".
322  */
323 static const char *next_line(const char *line, size_t len)
324 {
325         const char *nl = memchr(line, '\n', len);
326         if (!nl)
327                 return line + len; /* incomplete line */
328         return nl + 1;
329 }
330
331 static int generate_push_cert(struct strbuf *req_buf,
332                               const struct ref *remote_refs,
333                               struct send_pack_args *args,
334                               const char *cap_string,
335                               const char *push_cert_nonce)
336 {
337         const struct ref *ref;
338         struct string_list_item *item;
339         char *signing_key = xstrdup(get_signing_key());
340         const char *cp, *np;
341         struct strbuf cert = STRBUF_INIT;
342         int update_seen = 0;
343
344         strbuf_addstr(&cert, "certificate version 0.1\n");
345         strbuf_addf(&cert, "pusher %s ", signing_key);
346         datestamp(&cert);
347         strbuf_addch(&cert, '\n');
348         if (args->url && *args->url) {
349                 char *anon_url = transport_anonymize_url(args->url);
350                 strbuf_addf(&cert, "pushee %s\n", anon_url);
351                 free(anon_url);
352         }
353         if (push_cert_nonce[0])
354                 strbuf_addf(&cert, "nonce %s\n", push_cert_nonce);
355         if (args->push_options)
356                 for_each_string_list_item(item, args->push_options)
357                         strbuf_addf(&cert, "push-option %s\n", item->string);
358         strbuf_addstr(&cert, "\n");
359
360         for (ref = remote_refs; ref; ref = ref->next) {
361                 if (check_to_send_update(ref, args) < 0)
362                         continue;
363                 update_seen = 1;
364                 strbuf_addf(&cert, "%s %s %s\n",
365                             oid_to_hex(&ref->old_oid),
366                             oid_to_hex(&ref->new_oid),
367                             ref->name);
368         }
369         if (!update_seen)
370                 goto free_return;
371
372         if (sign_buffer(&cert, &cert, signing_key))
373                 die(_("failed to sign the push certificate"));
374
375         packet_buf_write(req_buf, "push-cert%c%s", 0, cap_string);
376         for (cp = cert.buf; cp < cert.buf + cert.len; cp = np) {
377                 np = next_line(cp, cert.buf + cert.len - cp);
378                 packet_buf_write(req_buf,
379                                  "%.*s", (int)(np - cp), cp);
380         }
381         packet_buf_write(req_buf, "push-cert-end\n");
382
383 free_return:
384         free(signing_key);
385         strbuf_release(&cert);
386         return update_seen;
387 }
388
389 #define NONCE_LEN_LIMIT 256
390
391 static void reject_invalid_nonce(const char *nonce, int len)
392 {
393         int i = 0;
394
395         if (NONCE_LEN_LIMIT <= len)
396                 die("the receiving end asked to sign an invalid nonce <%.*s>",
397                     len, nonce);
398
399         for (i = 0; i < len; i++) {
400                 int ch = nonce[i] & 0xFF;
401                 if (isalnum(ch) ||
402                     ch == '-' || ch == '.' ||
403                     ch == '/' || ch == '+' ||
404                     ch == '=' || ch == '_')
405                         continue;
406                 die("the receiving end asked to sign an invalid nonce <%.*s>",
407                     len, nonce);
408         }
409 }
410
411 int send_pack(struct send_pack_args *args,
412               int fd[], struct child_process *conn,
413               struct ref *remote_refs,
414               struct oid_array *extra_have)
415 {
416         int in = fd[0];
417         int out = fd[1];
418         struct strbuf req_buf = STRBUF_INIT;
419         struct strbuf cap_buf = STRBUF_INIT;
420         struct ref *ref;
421         int need_pack_data = 0;
422         int allow_deleting_refs = 0;
423         int status_report = 0;
424         int use_sideband = 0;
425         int quiet_supported = 0;
426         int agent_supported = 0;
427         int advertise_sid = 0;
428         int use_atomic = 0;
429         int atomic_supported = 0;
430         int use_push_options = 0;
431         int push_options_supported = 0;
432         int object_format_supported = 0;
433         unsigned cmds_sent = 0;
434         int ret;
435         struct async demux;
436         const char *push_cert_nonce = NULL;
437         struct packet_reader reader;
438
439         git_config_get_bool("transfer.advertisesid", &advertise_sid);
440
441         /* Does the other end support the reporting? */
442         if (server_supports("report-status-v2"))
443                 status_report = 2;
444         else if (server_supports("report-status"))
445                 status_report = 1;
446         if (server_supports("delete-refs"))
447                 allow_deleting_refs = 1;
448         if (server_supports("ofs-delta"))
449                 args->use_ofs_delta = 1;
450         if (server_supports("side-band-64k"))
451                 use_sideband = 1;
452         if (server_supports("quiet"))
453                 quiet_supported = 1;
454         if (server_supports("agent"))
455                 agent_supported = 1;
456         if (!server_supports("session-id"))
457                 advertise_sid = 0;
458         if (server_supports("no-thin"))
459                 args->use_thin_pack = 0;
460         if (server_supports("atomic"))
461                 atomic_supported = 1;
462         if (server_supports("push-options"))
463                 push_options_supported = 1;
464
465         if (!server_supports_hash(the_hash_algo->name, &object_format_supported))
466                 die(_("the receiving end does not support this repository's hash algorithm"));
467
468         if (args->push_cert != SEND_PACK_PUSH_CERT_NEVER) {
469                 int len;
470                 push_cert_nonce = server_feature_value("push-cert", &len);
471                 if (push_cert_nonce) {
472                         reject_invalid_nonce(push_cert_nonce, len);
473                         push_cert_nonce = xmemdupz(push_cert_nonce, len);
474                 } else if (args->push_cert == SEND_PACK_PUSH_CERT_ALWAYS) {
475                         die(_("the receiving end does not support --signed push"));
476                 } else if (args->push_cert == SEND_PACK_PUSH_CERT_IF_ASKED) {
477                         warning(_("not sending a push certificate since the"
478                                   " receiving end does not support --signed"
479                                   " push"));
480                 }
481         }
482
483         if (!remote_refs) {
484                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
485                         "Perhaps you should specify a branch.\n");
486                 return 0;
487         }
488         if (args->atomic && !atomic_supported)
489                 die(_("the receiving end does not support --atomic push"));
490
491         use_atomic = atomic_supported && args->atomic;
492
493         if (args->push_options && !push_options_supported)
494                 die(_("the receiving end does not support push options"));
495
496         use_push_options = push_options_supported && args->push_options;
497
498         if (status_report == 1)
499                 strbuf_addstr(&cap_buf, " report-status");
500         else if (status_report == 2)
501                 strbuf_addstr(&cap_buf, " report-status-v2");
502         if (use_sideband)
503                 strbuf_addstr(&cap_buf, " side-band-64k");
504         if (quiet_supported && (args->quiet || !args->progress))
505                 strbuf_addstr(&cap_buf, " quiet");
506         if (use_atomic)
507                 strbuf_addstr(&cap_buf, " atomic");
508         if (use_push_options)
509                 strbuf_addstr(&cap_buf, " push-options");
510         if (object_format_supported)
511                 strbuf_addf(&cap_buf, " object-format=%s", the_hash_algo->name);
512         if (agent_supported)
513                 strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());
514         if (advertise_sid)
515                 strbuf_addf(&cap_buf, " session-id=%s", trace2_session_id());
516
517         /*
518          * NEEDSWORK: why does delete-refs have to be so specific to
519          * send-pack machinery that set_ref_status_for_push() cannot
520          * set this bit for us???
521          */
522         for (ref = remote_refs; ref; ref = ref->next)
523                 if (ref->deletion && !allow_deleting_refs)
524                         ref->status = REF_STATUS_REJECT_NODELETE;
525
526         /*
527          * Clear the status for each ref and see if we need to send
528          * the pack data.
529          */
530         for (ref = remote_refs; ref; ref = ref->next) {
531                 switch (check_to_send_update(ref, args)) {
532                 case 0: /* no error */
533                         break;
534                 case CHECK_REF_STATUS_REJECTED:
535                         /*
536                          * When we know the server would reject a ref update if
537                          * we were to send it and we're trying to send the refs
538                          * atomically, abort the whole operation.
539                          */
540                         if (use_atomic) {
541                                 strbuf_release(&req_buf);
542                                 strbuf_release(&cap_buf);
543                                 reject_atomic_push(remote_refs, args->send_mirror);
544                                 error("atomic push failed for ref %s. status: %d\n",
545                                       ref->name, ref->status);
546                                 return args->porcelain ? 0 : -1;
547                         }
548                         /* else fallthrough */
549                 default:
550                         continue;
551                 }
552                 if (!ref->deletion)
553                         need_pack_data = 1;
554
555                 if (args->dry_run || !status_report)
556                         ref->status = REF_STATUS_OK;
557                 else
558                         ref->status = REF_STATUS_EXPECTING_REPORT;
559         }
560
561         if (!args->dry_run)
562                 advertise_shallow_grafts_buf(&req_buf);
563
564         /*
565          * Finally, tell the other end!
566          */
567         if (!args->dry_run && push_cert_nonce)
568                 cmds_sent = generate_push_cert(&req_buf, remote_refs, args,
569                                                cap_buf.buf, push_cert_nonce);
570         else if (!args->dry_run)
571                 for (ref = remote_refs; ref; ref = ref->next) {
572                         char *old_hex, *new_hex;
573
574                         if (check_to_send_update(ref, args) < 0)
575                                 continue;
576
577                         old_hex = oid_to_hex(&ref->old_oid);
578                         new_hex = oid_to_hex(&ref->new_oid);
579                         if (!cmds_sent) {
580                                 packet_buf_write(&req_buf,
581                                                  "%s %s %s%c%s",
582                                                  old_hex, new_hex, ref->name, 0,
583                                                  cap_buf.buf);
584                                 cmds_sent = 1;
585                         } else {
586                                 packet_buf_write(&req_buf, "%s %s %s",
587                                                  old_hex, new_hex, ref->name);
588                         }
589                 }
590
591         if (use_push_options) {
592                 struct string_list_item *item;
593
594                 packet_buf_flush(&req_buf);
595                 for_each_string_list_item(item, args->push_options)
596                         packet_buf_write(&req_buf, "%s", item->string);
597         }
598
599         if (args->stateless_rpc) {
600                 if (!args->dry_run && (cmds_sent || is_repository_shallow(the_repository))) {
601                         packet_buf_flush(&req_buf);
602                         send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
603                 }
604         } else {
605                 write_or_die(out, req_buf.buf, req_buf.len);
606                 packet_flush(out);
607         }
608         strbuf_release(&req_buf);
609         strbuf_release(&cap_buf);
610
611         if (use_sideband && cmds_sent) {
612                 memset(&demux, 0, sizeof(demux));
613                 demux.proc = sideband_demux;
614                 demux.data = fd;
615                 demux.out = -1;
616                 demux.isolate_sigpipe = 1;
617                 if (start_async(&demux))
618                         die("send-pack: unable to fork off sideband demultiplexer");
619                 in = demux.out;
620         }
621
622         packet_reader_init(&reader, in, NULL, 0,
623                            PACKET_READ_CHOMP_NEWLINE |
624                            PACKET_READ_DIE_ON_ERR_PACKET);
625
626         if (need_pack_data && cmds_sent) {
627                 if (pack_objects(out, remote_refs, extra_have, args) < 0) {
628                         if (args->stateless_rpc)
629                                 close(out);
630                         if (git_connection_is_socket(conn))
631                                 shutdown(fd[0], SHUT_WR);
632
633                         /*
634                          * Do not even bother with the return value; we know we
635                          * are failing, and just want the error() side effects,
636                          * as well as marking refs with their remote status (if
637                          * we get one).
638                          */
639                         if (status_report)
640                                 receive_status(&reader, remote_refs);
641
642                         if (use_sideband) {
643                                 close(demux.out);
644                                 finish_async(&demux);
645                         }
646                         fd[1] = -1;
647                         return -1;
648                 }
649                 if (!args->stateless_rpc)
650                         /* Closed by pack_objects() via start_command() */
651                         fd[1] = -1;
652         }
653         if (args->stateless_rpc && cmds_sent)
654                 packet_flush(out);
655
656         if (status_report && cmds_sent)
657                 ret = receive_status(&reader, remote_refs);
658         else
659                 ret = 0;
660         if (args->stateless_rpc)
661                 packet_flush(out);
662
663         if (use_sideband && cmds_sent) {
664                 close(demux.out);
665                 if (finish_async(&demux)) {
666                         error("error in sideband demultiplexer");
667                         ret = -1;
668                 }
669         }
670
671         if (ret < 0)
672                 return ret;
673
674         if (args->porcelain)
675                 return 0;
676
677         for (ref = remote_refs; ref; ref = ref->next) {
678                 switch (ref->status) {
679                 case REF_STATUS_NONE:
680                 case REF_STATUS_UPTODATE:
681                 case REF_STATUS_OK:
682                         break;
683                 default:
684                         return -1;
685                 }
686         }
687         return 0;
688 }