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
 248         default:
 249         case REF_STATUS_EXPECTING_REPORT:
 250                 /* already passed checks on the local side */
 251         case REF_STATUS_OK:
 252                 /* of course this is OK */
 253                 return 0;
 254         }
 255 }
 256
 257 /*
 258  * the beginning of the next line, or the end of buffer.
 259  *
 260  * NEEDSWORK: perhaps move this to git-compat-util.h or somewhere and
 261  * convert many similar uses found by "git grep -A4 memchr".
 262  */
 263 static const char *next_line(const char *line, size_t len)
 264 {
 265         const char *nl = memchr(line, '\n', len);
 266         if (!nl)
 267                 return line + len; /* incomplete line */
 268         return nl + 1;
 269 }
 270
 271 static int generate_push_cert(struct strbuf *req_buf,
 272                               const struct ref *remote_refs,
 273                               struct send_pack_args *args,
 274                               const char *cap_string,
 275                               const char *push_cert_nonce)
 276 {
 277         const struct ref *ref;
 278         struct string_list_item *item;
 279         char *signing_key = xstrdup(get_signing_key());
 280         const char *cp, *np;
 281         struct strbuf cert = STRBUF_INIT;
 282         int update_seen = 0;
 283
 284         strbuf_addstr(&cert, "certificate version 0.1\n");
 285         strbuf_addf(&cert, "pusher %s ", signing_key);
 286         datestamp(&cert);
 287         strbuf_addch(&cert, '\n');
 288         if (args->url && *args->url) {
 289                 char *anon_url = transport_anonymize_url(args->url);
 290                 strbuf_addf(&cert, "pushee %s\n", anon_url);
 291                 free(anon_url);
 292         }
 293         if (push_cert_nonce[0])
 294                 strbuf_addf(&cert, "nonce %s\n", push_cert_nonce);
 295         if (args->push_options)
 296                 for_each_string_list_item(item, args->push_options)
 297                         strbuf_addf(&cert, "push-option %s\n", item->string);
 298         strbuf_addstr(&cert, "\n");
 299
 300         for (ref = remote_refs; ref; ref = ref->next) {
 301                 if (check_to_send_update(ref, args) < 0)
 302                         continue;
 303                 update_seen = 1;
 304                 strbuf_addf(&cert, "%s %s %s\n",
 305                             oid_to_hex(&ref->old_oid),
 306                             oid_to_hex(&ref->new_oid),
 307                             ref->name);
 308         }
 309         if (!update_seen)
 310                 goto free_return;
 311
 312         if (sign_buffer(&cert, &cert, signing_key))
 313                 die(_("failed to sign the push certificate"));
 314
 315         packet_buf_write(req_buf, "push-cert%c%s", 0, cap_string);
 316         for (cp = cert.buf; cp < cert.buf + cert.len; cp = np) {
 317                 np = next_line(cp, cert.buf + cert.len - cp);
 318                 packet_buf_write(req_buf,
 319                                  "%.*s", (int)(np - cp), cp);
 320         }
 321         packet_buf_write(req_buf, "push-cert-end\n");
 322
 323 free_return:
 324         free(signing_key);
 325         strbuf_release(&cert);
 326         return update_seen;
 327 }
 328
 329 #define NONCE_LEN_LIMIT 256
 330
 331 static void reject_invalid_nonce(const char *nonce, int len)
 332 {
 333         int i = 0;
 334
 335         if (NONCE_LEN_LIMIT <= len)
 336                 die("the receiving end asked to sign an invalid nonce <%.*s>",
 337                     len, nonce);
 338
 339         for (i = 0; i < len; i++) {
 340                 int ch = nonce[i] & 0xFF;
 341                 if (isalnum(ch) ||
 342                     ch == '-' || ch == '.' ||
 343                     ch == '/' || ch == '+' ||
 344                     ch == '=' || ch == '_')
 345                         continue;
 346                 die("the receiving end asked to sign an invalid nonce <%.*s>",
 347                     len, nonce);
 348         }
 349 }
 350
 351 int send_pack(struct send_pack_args *args,
 352               int fd[], struct child_process *conn,
 353               struct ref *remote_refs,
 354               struct oid_array *extra_have)
 355 {
 356         int in = fd[0];
 357         int out = fd[1];
 358         struct strbuf req_buf = STRBUF_INIT;
 359         struct strbuf cap_buf = STRBUF_INIT;
 360         struct ref *ref;
 361         int need_pack_data = 0;
 362         int allow_deleting_refs = 0;
 363         int status_report = 0;
 364         int use_sideband = 0;
 365         int quiet_supported = 0;
 366         int agent_supported = 0;
 367         int use_atomic = 0;
 368         int atomic_supported = 0;
 369         int use_push_options = 0;
 370         int push_options_supported = 0;
 371         int object_format_supported = 0;
 372         unsigned cmds_sent = 0;
 373         int ret;
 374         struct async demux;
 375         const char *push_cert_nonce = NULL;
 376         struct packet_reader reader;
 377
 378         /* Does the other end support the reporting? */
 379         if (server_supports("report-status"))
 380                 status_report = 1;
 381         if (server_supports("delete-refs"))
 382                 allow_deleting_refs = 1;
 383         if (server_supports("ofs-delta"))
 384                 args->use_ofs_delta = 1;
 385         if (server_supports("side-band-64k"))
 386                 use_sideband = 1;
 387         if (server_supports("quiet"))
 388                 quiet_supported = 1;
 389         if (server_supports("agent"))
 390                 agent_supported = 1;
 391         if (server_supports("no-thin"))
 392                 args->use_thin_pack = 0;
 393         if (server_supports("atomic"))
 394                 atomic_supported = 1;
 395         if (server_supports("push-options"))
 396                 push_options_supported = 1;
 397
 398         if (!server_supports_hash(the_hash_algo->name, &object_format_supported))
 399                 die(_("the receiving end does not support this repository's hash algorithm"));
 400
 401         if (args->push_cert != SEND_PACK_PUSH_CERT_NEVER) {
 402                 int len;
 403                 push_cert_nonce = server_feature_value("push-cert", &len);
 404                 if (push_cert_nonce) {
 405                         reject_invalid_nonce(push_cert_nonce, len);
 406                         push_cert_nonce = xmemdupz(push_cert_nonce, len);
 407                 } else if (args->push_cert == SEND_PACK_PUSH_CERT_ALWAYS) {
 408                         die(_("the receiving end does not support --signed push"));
 409                 } else if (args->push_cert == SEND_PACK_PUSH_CERT_IF_ASKED) {
 410                         warning(_("not sending a push certificate since the"
 411                                   " receiving end does not support --signed"
 412                                   " push"));
 413                 }
 414         }
 415
 416         if (!remote_refs) {
 417                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 418                         "Perhaps you should specify a branch.\n");
 419                 return 0;
 420         }
 421         if (args->atomic && !atomic_supported)
 422                 die(_("the receiving end does not support --atomic push"));
 423
 424         use_atomic = atomic_supported && args->atomic;
 425
 426         if (args->push_options && !push_options_supported)
 427                 die(_("the receiving end does not support push options"));
 428
 429         use_push_options = push_options_supported && args->push_options;
 430
 431         if (status_report)
 432                 strbuf_addstr(&cap_buf, " report-status");
 433         if (use_sideband)
 434                 strbuf_addstr(&cap_buf, " side-band-64k");
 435         if (quiet_supported && (args->quiet || !args->progress))
 436                 strbuf_addstr(&cap_buf, " quiet");
 437         if (use_atomic)
 438                 strbuf_addstr(&cap_buf, " atomic");
 439         if (use_push_options)
 440                 strbuf_addstr(&cap_buf, " push-options");
 441         if (object_format_supported)
 442                 strbuf_addf(&cap_buf, " object-format=%s", the_hash_algo->name);
 443         if (agent_supported)
 444                 strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());
 445
 446         /*
 447          * NEEDSWORK: why does delete-refs have to be so specific to
 448          * send-pack machinery that set_ref_status_for_push() cannot
 449          * set this bit for us???
 450          */
 451         for (ref = remote_refs; ref; ref = ref->next)
 452                 if (ref->deletion && !allow_deleting_refs)
 453                         ref->status = REF_STATUS_REJECT_NODELETE;
 454
 455         /*
 456          * Clear the status for each ref and see if we need to send
 457          * the pack data.
 458          */
 459         for (ref = remote_refs; ref; ref = ref->next) {
 460                 switch (check_to_send_update(ref, args)) {
 461                 case 0: /* no error */
 462                         break;
 463                 case CHECK_REF_STATUS_REJECTED:
 464                         /*
 465                          * When we know the server would reject a ref update if
 466                          * we were to send it and we're trying to send the refs
 467                          * atomically, abort the whole operation.
 468                          */
 469                         if (use_atomic) {
 470                                 strbuf_release(&req_buf);
 471                                 strbuf_release(&cap_buf);
 472                                 reject_atomic_push(remote_refs, args->send_mirror);
 473                                 error("atomic push failed for ref %s. status: %d\n",
 474                                       ref->name, ref->status);
 475                                 return args->porcelain ? 0 : -1;
 476                         }
 477                         /* else fallthrough */
 478                 default:
 479                         continue;
 480                 }
 481                 if (!ref->deletion)
 482                         need_pack_data = 1;
 483
 484                 if (args->dry_run || !status_report)
 485                         ref->status = REF_STATUS_OK;
 486                 else
 487                         ref->status = REF_STATUS_EXPECTING_REPORT;
 488         }
 489
 490         if (!args->dry_run)
 491                 advertise_shallow_grafts_buf(&req_buf);
 492
 493         /*
 494          * Finally, tell the other end!
 495          */
 496         if (!args->dry_run && push_cert_nonce)
 497                 cmds_sent = generate_push_cert(&req_buf, remote_refs, args,
 498                                                cap_buf.buf, push_cert_nonce);
 499         else if (!args->dry_run)
 500                 for (ref = remote_refs; ref; ref = ref->next) {
 501                         char *old_hex, *new_hex;
 502
 503                         if (check_to_send_update(ref, args) < 0)
 504                                 continue;
 505
 506                         old_hex = oid_to_hex(&ref->old_oid);
 507                         new_hex = oid_to_hex(&ref->new_oid);
 508                         if (!cmds_sent) {
 509                                 packet_buf_write(&req_buf,
 510                                                  "%s %s %s%c%s",
 511                                                  old_hex, new_hex, ref->name, 0,
 512                                                  cap_buf.buf);
 513                                 cmds_sent = 1;
 514                         } else {
 515                                 packet_buf_write(&req_buf, "%s %s %s",
 516                                                  old_hex, new_hex, ref->name);
 517                         }
 518                 }
 519
 520         if (use_push_options) {
 521                 struct string_list_item *item;
 522
 523                 packet_buf_flush(&req_buf);
 524                 for_each_string_list_item(item, args->push_options)
 525                         packet_buf_write(&req_buf, "%s", item->string);
 526         }
 527
 528         if (args->stateless_rpc) {
 529                 if (!args->dry_run && (cmds_sent || is_repository_shallow(the_repository))) {
 530                         packet_buf_flush(&req_buf);
 531                         send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
 532                 }
 533         } else {
 534                 write_or_die(out, req_buf.buf, req_buf.len);
 535                 packet_flush(out);
 536         }
 537         strbuf_release(&req_buf);
 538         strbuf_release(&cap_buf);
 539
 540         if (use_sideband && cmds_sent) {
 541                 memset(&demux, 0, sizeof(demux));
 542                 demux.proc = sideband_demux;
 543                 demux.data = fd;
 544                 demux.out = -1;
 545                 demux.isolate_sigpipe = 1;
 546                 if (start_async(&demux))
 547                         die("send-pack: unable to fork off sideband demultiplexer");
 548                 in = demux.out;
 549         }
 550
 551         packet_reader_init(&reader, in, NULL, 0,
 552                            PACKET_READ_CHOMP_NEWLINE |
 553                            PACKET_READ_DIE_ON_ERR_PACKET);
 554
 555         if (need_pack_data && cmds_sent) {
 556                 if (pack_objects(out, remote_refs, extra_have, args) < 0) {
 557                         if (args->stateless_rpc)
 558                                 close(out);
 559                         if (git_connection_is_socket(conn))
 560                                 shutdown(fd[0], SHUT_WR);
 561
 562                         /*
 563                          * Do not even bother with the return value; we know we
 564                          * are failing, and just want the error() side effects,
 565                          * as well as marking refs with their remote status (if
 566                          * we get one).
 567                          */
 568                         if (status_report)
 569                                 receive_status(&reader, remote_refs);
 570
 571                         if (use_sideband) {
 572                                 close(demux.out);
 573                                 finish_async(&demux);
 574                         }
 575                         fd[1] = -1;
 576                         return -1;
 577                 }
 578                 if (!args->stateless_rpc)
 579                         /* Closed by pack_objects() via start_command() */
 580                         fd[1] = -1;
 581         }
 582         if (args->stateless_rpc && cmds_sent)
 583                 packet_flush(out);
 584
 585         if (status_report && cmds_sent)
 586                 ret = receive_status(&reader, remote_refs);
 587         else
 588                 ret = 0;
 589         if (args->stateless_rpc)
 590                 packet_flush(out);
 591
 592         if (use_sideband && cmds_sent) {
 593                 close(demux.out);
 594                 if (finish_async(&demux)) {
 595                         error("error in sideband demultiplexer");
 596                         ret = -1;
 597                 }
 598         }
 599
 600         if (ret < 0)
 601                 return ret;
 602
 603         if (args->porcelain)
 604                 return 0;
 605
 606         for (ref = remote_refs; ref; ref = ref->next) {
 607                 switch (ref->status) {
 608                 case REF_STATUS_NONE:
 609                 case REF_STATUS_UPTODATE:
 610                 case REF_STATUS_OK:
 611                         break;
 612                 default:
 613                         return -1;
 614                 }
 615         }
 616         return 0;
 617 }