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
 158         hint = NULL;
 159         ret = receive_unpack_status(reader);
 160         while (1) {
 161                 const char *refname;
 162                 char *msg;
 163                 if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 164                         break;
 165                 if (!starts_with(reader->line, "ok ") && !starts_with(reader->line, "ng ")) {
 166                         error("invalid ref status from remote: %s", reader->line);
 167                         ret = -1;
 168                         break;
 169                 }
 170
 171                 refname = reader->line + 3;
 172                 msg = strchr(refname, ' ');
 173                 if (msg)
 174                         *msg++ = '\0';
 175
 176                 /* first try searching at our hint, falling back to all refs */
 177                 if (hint)
 178                         hint = find_ref_by_name(hint, refname);
 179                 if (!hint)
 180                         hint = find_ref_by_name(refs, refname);
 181                 if (!hint) {
 182                         warning("remote reported status on unknown ref: %s",
 183                                         refname);
 184                         continue;
 185                 }
 186                 if (hint->status != REF_STATUS_EXPECTING_REPORT) {
 187                         warning("remote reported status on unexpected ref: %s",
 188                                         refname);
 189                         continue;
 190                 }
 191
 192                 if (reader->line[0] == 'o' && reader->line[1] == 'k')
 193                         hint->status = REF_STATUS_OK;
 194                 else
 195                         hint->status = REF_STATUS_REMOTE_REJECT;
 196                 hint->remote_status = xstrdup_or_null(msg);
 197                 /* start our next search from the next ref */
 198                 hint = hint->next;
 199         }
 200         return ret;
 201 }
 202
 203 static int sideband_demux(int in, int out, void *data)
 204 {
 205         int *fd = data, ret;
 206         if (async_with_fork())
 207                 close(fd[1]);
 208         ret = recv_sideband("send-pack", fd[0], out);
 209         close(out);
 210         return ret;
 211 }
 212
 213 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
 214 {
 215         struct strbuf *sb = cb;
 216         if (graft->nr_parent == -1)
 217                 packet_buf_write(sb, "shallow %s\n", oid_to_hex(&graft->oid));
 218         return 0;
 219 }
 220
 221 static void advertise_shallow_grafts_buf(struct strbuf *sb)
 222 {
 223         if (!is_repository_shallow(the_repository))
 224                 return;
 225         for_each_commit_graft(advertise_shallow_grafts_cb, sb);
 226 }
 227
 228 #define CHECK_REF_NO_PUSH -1
 229 #define CHECK_REF_STATUS_REJECTED -2
 230 #define CHECK_REF_UPTODATE -3
 231 static int check_to_send_update(const struct ref *ref, const struct send_pack_args *args)
 232 {
 233         if (!ref->peer_ref && !args->send_mirror)
 234                 return CHECK_REF_NO_PUSH;
 235
 236         /* Check for statuses set by set_ref_status_for_push() */
 237         switch (ref->status) {
 238         case REF_STATUS_REJECT_NONFASTFORWARD:
 239         case REF_STATUS_REJECT_ALREADY_EXISTS:
 240         case REF_STATUS_REJECT_FETCH_FIRST:
 241         case REF_STATUS_REJECT_NEEDS_FORCE:
 242         case REF_STATUS_REJECT_STALE:
 243         case REF_STATUS_REJECT_NODELETE:
 244                 return CHECK_REF_STATUS_REJECTED;
 245         case REF_STATUS_UPTODATE:
 246                 return CHECK_REF_UPTODATE;
 247         default:
 248                 return 0;
 249         }
 250 }
 251
 252 /*
 253  * the beginning of the next line, or the end of buffer.
 254  *
 255  * NEEDSWORK: perhaps move this to git-compat-util.h or somewhere and
 256  * convert many similar uses found by "git grep -A4 memchr".
 257  */
 258 static const char *next_line(const char *line, size_t len)
 259 {
 260         const char *nl = memchr(line, '\n', len);
 261         if (!nl)
 262                 return line + len; /* incomplete line */
 263         return nl + 1;
 264 }
 265
 266 static int generate_push_cert(struct strbuf *req_buf,
 267                               const struct ref *remote_refs,
 268                               struct send_pack_args *args,
 269                               const char *cap_string,
 270                               const char *push_cert_nonce)
 271 {
 272         const struct ref *ref;
 273         struct string_list_item *item;
 274         char *signing_key = xstrdup(get_signing_key());
 275         const char *cp, *np;
 276         struct strbuf cert = STRBUF_INIT;
 277         int update_seen = 0;
 278
 279         strbuf_addstr(&cert, "certificate version 0.1\n");
 280         strbuf_addf(&cert, "pusher %s ", signing_key);
 281         datestamp(&cert);
 282         strbuf_addch(&cert, '\n');
 283         if (args->url && *args->url) {
 284                 char *anon_url = transport_anonymize_url(args->url);
 285                 strbuf_addf(&cert, "pushee %s\n", anon_url);
 286                 free(anon_url);
 287         }
 288         if (push_cert_nonce[0])
 289                 strbuf_addf(&cert, "nonce %s\n", push_cert_nonce);
 290         if (args->push_options)
 291                 for_each_string_list_item(item, args->push_options)
 292                         strbuf_addf(&cert, "push-option %s\n", item->string);
 293         strbuf_addstr(&cert, "\n");
 294
 295         for (ref = remote_refs; ref; ref = ref->next) {
 296                 if (check_to_send_update(ref, args) < 0)
 297                         continue;
 298                 update_seen = 1;
 299                 strbuf_addf(&cert, "%s %s %s\n",
 300                             oid_to_hex(&ref->old_oid),
 301                             oid_to_hex(&ref->new_oid),
 302                             ref->name);
 303         }
 304         if (!update_seen)
 305                 goto free_return;
 306
 307         if (sign_buffer(&cert, &cert, signing_key))
 308                 die(_("failed to sign the push certificate"));
 309
 310         packet_buf_write(req_buf, "push-cert%c%s", 0, cap_string);
 311         for (cp = cert.buf; cp < cert.buf + cert.len; cp = np) {
 312                 np = next_line(cp, cert.buf + cert.len - cp);
 313                 packet_buf_write(req_buf,
 314                                  "%.*s", (int)(np - cp), cp);
 315         }
 316         packet_buf_write(req_buf, "push-cert-end\n");
 317
 318 free_return:
 319         free(signing_key);
 320         strbuf_release(&cert);
 321         return update_seen;
 322 }
 323
 324 #define NONCE_LEN_LIMIT 256
 325
 326 static void reject_invalid_nonce(const char *nonce, int len)
 327 {
 328         int i = 0;
 329
 330         if (NONCE_LEN_LIMIT <= len)
 331                 die("the receiving end asked to sign an invalid nonce <%.*s>",
 332                     len, nonce);
 333
 334         for (i = 0; i < len; i++) {
 335                 int ch = nonce[i] & 0xFF;
 336                 if (isalnum(ch) ||
 337                     ch == '-' || ch == '.' ||
 338                     ch == '/' || ch == '+' ||
 339                     ch == '=' || ch == '_')
 340                         continue;
 341                 die("the receiving end asked to sign an invalid nonce <%.*s>",
 342                     len, nonce);
 343         }
 344 }
 345
 346 int send_pack(struct send_pack_args *args,
 347               int fd[], struct child_process *conn,
 348               struct ref *remote_refs,
 349               struct oid_array *extra_have)
 350 {
 351         int in = fd[0];
 352         int out = fd[1];
 353         struct strbuf req_buf = STRBUF_INIT;
 354         struct strbuf cap_buf = STRBUF_INIT;
 355         struct ref *ref;
 356         int need_pack_data = 0;
 357         int allow_deleting_refs = 0;
 358         int status_report = 0;
 359         int use_sideband = 0;
 360         int quiet_supported = 0;
 361         int agent_supported = 0;
 362         int use_atomic = 0;
 363         int atomic_supported = 0;
 364         int use_push_options = 0;
 365         int push_options_supported = 0;
 366         int object_format_supported = 0;
 367         unsigned cmds_sent = 0;
 368         int ret;
 369         struct async demux;
 370         const char *push_cert_nonce = NULL;
 371         struct packet_reader reader;
 372
 373         /* Does the other end support the reporting? */
 374         if (server_supports("report-status"))
 375                 status_report = 1;
 376         if (server_supports("delete-refs"))
 377                 allow_deleting_refs = 1;
 378         if (server_supports("ofs-delta"))
 379                 args->use_ofs_delta = 1;
 380         if (server_supports("side-band-64k"))
 381                 use_sideband = 1;
 382         if (server_supports("quiet"))
 383                 quiet_supported = 1;
 384         if (server_supports("agent"))
 385                 agent_supported = 1;
 386         if (server_supports("no-thin"))
 387                 args->use_thin_pack = 0;
 388         if (server_supports("atomic"))
 389                 atomic_supported = 1;
 390         if (server_supports("push-options"))
 391                 push_options_supported = 1;
 392
 393         if (!server_supports_hash(the_hash_algo->name, &object_format_supported))
 394                 die(_("the receiving end does not support this repository's hash algorithm"));
 395
 396         if (args->push_cert != SEND_PACK_PUSH_CERT_NEVER) {
 397                 int len;
 398                 push_cert_nonce = server_feature_value("push-cert", &len);
 399                 if (push_cert_nonce) {
 400                         reject_invalid_nonce(push_cert_nonce, len);
 401                         push_cert_nonce = xmemdupz(push_cert_nonce, len);
 402                 } else if (args->push_cert == SEND_PACK_PUSH_CERT_ALWAYS) {
 403                         die(_("the receiving end does not support --signed push"));
 404                 } else if (args->push_cert == SEND_PACK_PUSH_CERT_IF_ASKED) {
 405                         warning(_("not sending a push certificate since the"
 406                                   " receiving end does not support --signed"
 407                                   " push"));
 408                 }
 409         }
 410
 411         if (!remote_refs) {
 412                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 413                         "Perhaps you should specify a branch.\n");
 414                 return 0;
 415         }
 416         if (args->atomic && !atomic_supported)
 417                 die(_("the receiving end does not support --atomic push"));
 418
 419         use_atomic = atomic_supported && args->atomic;
 420
 421         if (args->push_options && !push_options_supported)
 422                 die(_("the receiving end does not support push options"));
 423
 424         use_push_options = push_options_supported && args->push_options;
 425
 426         if (status_report)
 427                 strbuf_addstr(&cap_buf, " report-status");
 428         if (use_sideband)
 429                 strbuf_addstr(&cap_buf, " side-band-64k");
 430         if (quiet_supported && (args->quiet || !args->progress))
 431                 strbuf_addstr(&cap_buf, " quiet");
 432         if (use_atomic)
 433                 strbuf_addstr(&cap_buf, " atomic");
 434         if (use_push_options)
 435                 strbuf_addstr(&cap_buf, " push-options");
 436         if (object_format_supported)
 437                 strbuf_addf(&cap_buf, " object-format=%s", the_hash_algo->name);
 438         if (agent_supported)
 439                 strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());
 440
 441         /*
 442          * NEEDSWORK: why does delete-refs have to be so specific to
 443          * send-pack machinery that set_ref_status_for_push() cannot
 444          * set this bit for us???
 445          */
 446         for (ref = remote_refs; ref; ref = ref->next)
 447                 if (ref->deletion && !allow_deleting_refs)
 448                         ref->status = REF_STATUS_REJECT_NODELETE;
 449
 450         if (!args->dry_run)
 451                 advertise_shallow_grafts_buf(&req_buf);
 452
 453         if (!args->dry_run && push_cert_nonce)
 454                 cmds_sent = generate_push_cert(&req_buf, remote_refs, args,
 455                                                cap_buf.buf, push_cert_nonce);
 456
 457         /*
 458          * Clear the status for each ref and see if we need to send
 459          * the pack data.
 460          */
 461         for (ref = remote_refs; ref; ref = ref->next) {
 462                 switch (check_to_send_update(ref, args)) {
 463                 case 0: /* no error */
 464                         break;
 465                 case CHECK_REF_STATUS_REJECTED:
 466                         /*
 467                          * When we know the server would reject a ref update if
 468                          * we were to send it and we're trying to send the refs
 469                          * atomically, abort the whole operation.
 470                          */
 471                         if (use_atomic) {
 472                                 strbuf_release(&req_buf);
 473                                 strbuf_release(&cap_buf);
 474                                 reject_atomic_push(remote_refs, args->send_mirror);
 475                                 error("atomic push failed for ref %s. status: %d\n",
 476                                       ref->name, ref->status);
 477                                 return args->porcelain ? 0 : -1;
 478                         }
 479                         /* else fallthrough */
 480                 default:
 481                         continue;
 482                 }
 483                 if (!ref->deletion)
 484                         need_pack_data = 1;
 485
 486                 if (args->dry_run || !status_report)
 487                         ref->status = REF_STATUS_OK;
 488                 else
 489                         ref->status = REF_STATUS_EXPECTING_REPORT;
 490         }
 491
 492         /*
 493          * Finally, tell the other end!
 494          */
 495         for (ref = remote_refs; ref; ref = ref->next) {
 496                 char *old_hex, *new_hex;
 497
 498                 if (args->dry_run || push_cert_nonce)
 499                         continue;
 500
 501                 if (check_to_send_update(ref, args) < 0)
 502                         continue;
 503
 504                 old_hex = oid_to_hex(&ref->old_oid);
 505                 new_hex = oid_to_hex(&ref->new_oid);
 506                 if (!cmds_sent) {
 507                         packet_buf_write(&req_buf,
 508                                          "%s %s %s%c%s",
 509                                          old_hex, new_hex, ref->name, 0,
 510                                          cap_buf.buf);
 511                         cmds_sent = 1;
 512                 } else {
 513                         packet_buf_write(&req_buf, "%s %s %s",
 514                                          old_hex, new_hex, ref->name);
 515                 }
 516         }
 517
 518         if (use_push_options) {
 519                 struct string_list_item *item;
 520
 521                 packet_buf_flush(&req_buf);
 522                 for_each_string_list_item(item, args->push_options)
 523                         packet_buf_write(&req_buf, "%s", item->string);
 524         }
 525
 526         if (args->stateless_rpc) {
 527                 if (!args->dry_run && (cmds_sent || is_repository_shallow(the_repository))) {
 528                         packet_buf_flush(&req_buf);
 529                         send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
 530                 }
 531         } else {
 532                 write_or_die(out, req_buf.buf, req_buf.len);
 533                 packet_flush(out);
 534         }
 535         strbuf_release(&req_buf);
 536         strbuf_release(&cap_buf);
 537
 538         if (use_sideband && cmds_sent) {
 539                 memset(&demux, 0, sizeof(demux));
 540                 demux.proc = sideband_demux;
 541                 demux.data = fd;
 542                 demux.out = -1;
 543                 demux.isolate_sigpipe = 1;
 544                 if (start_async(&demux))
 545                         die("send-pack: unable to fork off sideband demultiplexer");
 546                 in = demux.out;
 547         }
 548
 549         packet_reader_init(&reader, in, NULL, 0,
 550                            PACKET_READ_CHOMP_NEWLINE |
 551                            PACKET_READ_DIE_ON_ERR_PACKET);
 552
 553         if (need_pack_data && cmds_sent) {
 554                 if (pack_objects(out, remote_refs, extra_have, args) < 0) {
 555                         if (args->stateless_rpc)
 556                                 close(out);
 557                         if (git_connection_is_socket(conn))
 558                                 shutdown(fd[0], SHUT_WR);
 559
 560                         /*
 561                          * Do not even bother with the return value; we know we
 562                          * are failing, and just want the error() side effects,
 563                          * as well as marking refs with their remote status (if
 564                          * we get one).
 565                          */
 566                         if (status_report)
 567                                 receive_status(&reader, remote_refs);
 568
 569                         if (use_sideband) {
 570                                 close(demux.out);
 571                                 finish_async(&demux);
 572                         }
 573                         fd[1] = -1;
 574                         return -1;
 575                 }
 576                 if (!args->stateless_rpc)
 577                         /* Closed by pack_objects() via start_command() */
 578                         fd[1] = -1;
 579         }
 580         if (args->stateless_rpc && cmds_sent)
 581                 packet_flush(out);
 582
 583         if (status_report && cmds_sent)
 584                 ret = receive_status(&reader, remote_refs);
 585         else
 586                 ret = 0;
 587         if (args->stateless_rpc)
 588                 packet_flush(out);
 589
 590         if (use_sideband && cmds_sent) {
 591                 close(demux.out);
 592                 if (finish_async(&demux)) {
 593                         error("error in sideband demultiplexer");
 594                         ret = -1;
 595                 }
 596         }
 597
 598         if (ret < 0)
 599                 return ret;
 600
 601         if (args->porcelain)
 602                 return 0;
 603
 604         for (ref = remote_refs; ref; ref = ref->next) {
 605                 switch (ref->status) {
 606                 case REF_STATUS_NONE:
 607                 case REF_STATUS_UPTODATE:
 608                 case REF_STATUS_OK:
 609                         break;
 610                 default:
 611                         return -1;
 612                 }
 613         }
 614         return 0;
 615 }