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