git.oblomov.eu Git - git/blob - fetch-pack.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "config.h"
   4 #include "lockfile.h"
   5 #include "refs.h"
   6 #include "pkt-line.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "exec-cmd.h"
  10 #include "pack.h"
  11 #include "sideband.h"
  12 #include "fetch-pack.h"
  13 #include "remote.h"
  14 #include "run-command.h"
  15 #include "connect.h"
  16 #include "transport.h"
  17 #include "version.h"
  18 #include "sha1-array.h"
  19 #include "oidset.h"
  20 #include "packfile.h"
  21 #include "object-store.h"
  22 #include "connected.h"
  23 #include "fetch-negotiator.h"
  24 #include "fsck.h"
  25
  26 static int transfer_unpack_limit = -1;
  27 static int fetch_unpack_limit = -1;
  28 static int unpack_limit = 100;
  29 static int prefer_ofs_delta = 1;
  30 static int no_done;
  31 static int deepen_since_ok;
  32 static int deepen_not_ok;
  33 static int fetch_fsck_objects = -1;
  34 static int transfer_fsck_objects = -1;
  35 static int agent_supported;
  36 static int server_supports_filtering;
  37 static struct lock_file shallow_lock;
  38 static const char *alternate_shallow_file;
  39 static struct strbuf fsck_msg_types = STRBUF_INIT;
  40
  41 /* Remember to update object flag allocation in object.h */
  42 #define COMPLETE        (1U << 0)
  43 #define ALTERNATE       (1U << 1)
  44
  45 /*
  46  * After sending this many "have"s if we do not get any new ACK , we
  47  * give up traversing our history.
  48  */
  49 #define MAX_IN_VAIN 256
  50
  51 static int multi_ack, use_sideband;
  52 /* Allow specifying sha1 if it is a ref tip. */
  53 #define ALLOW_TIP_SHA1  01
  54 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  55 #define ALLOW_REACHABLE_SHA1    02
  56 static unsigned int allow_unadvertised_object_request;
  57
  58 __attribute__((format (printf, 2, 3)))
  59 static inline void print_verbose(const struct fetch_pack_args *args,
  60                                  const char *fmt, ...)
  61 {
  62         va_list params;
  63
  64         if (!args->verbose)
  65                 return;
  66
  67         va_start(params, fmt);
  68         vfprintf(stderr, fmt, params);
  69         va_end(params);
  70         fputc('\n', stderr);
  71 }
  72
  73 struct alternate_object_cache {
  74         struct object **items;
  75         size_t nr, alloc;
  76 };
  77
  78 static void cache_one_alternate(const struct object_id *oid,
  79                                 void *vcache)
  80 {
  81         struct alternate_object_cache *cache = vcache;
  82         struct object *obj = parse_object(the_repository, oid);
  83
  84         if (!obj || (obj->flags & ALTERNATE))
  85                 return;
  86
  87         obj->flags |= ALTERNATE;
  88         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  89         cache->items[cache->nr++] = obj;
  90 }
  91
  92 static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  93                                       void (*cb)(struct fetch_negotiator *,
  94                                                  struct object *))
  95 {
  96         static int initialized;
  97         static struct alternate_object_cache cache;
  98         size_t i;
  99
 100         if (!initialized) {
 101                 for_each_alternate_ref(cache_one_alternate, &cache);
 102                 initialized = 1;
 103         }
 104
 105         for (i = 0; i < cache.nr; i++)
 106                 cb(negotiator, cache.items[i]);
 107 }
 108
 109 static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 110                                const char *refname,
 111                                const struct object_id *oid)
 112 {
 113         struct object *o = deref_tag(the_repository,
 114                                      parse_object(the_repository, oid),
 115                                      refname, 0);
 116
 117         if (o && o->type == OBJ_COMMIT)
 118                 negotiator->add_tip(negotiator, (struct commit *)o);
 119
 120         return 0;
 121 }
 122
 123 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 124                                    int flag, void *cb_data)
 125 {
 126         return rev_list_insert_ref(cb_data, refname, oid);
 127 }
 128
 129 enum ack_type {
 130         NAK = 0,
 131         ACK,
 132         ACK_continue,
 133         ACK_common,
 134         ACK_ready
 135 };
 136
 137 static void consume_shallow_list(struct fetch_pack_args *args,
 138                                  struct packet_reader *reader)
 139 {
 140         if (args->stateless_rpc && args->deepen) {
 141                 /* If we sent a depth we will get back "duplicate"
 142                  * shallow and unshallow commands every time there
 143                  * is a block of have lines exchanged.
 144                  */
 145                 while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 146                         if (starts_with(reader->line, "shallow "))
 147                                 continue;
 148                         if (starts_with(reader->line, "unshallow "))
 149                                 continue;
 150                         die(_("git fetch-pack: expected shallow list"));
 151                 }
 152                 if (reader->status != PACKET_READ_FLUSH)
 153                         die(_("git fetch-pack: expected a flush packet after shallow list"));
 154         }
 155 }
 156
 157 static enum ack_type get_ack(struct packet_reader *reader,
 158                              struct object_id *result_oid)
 159 {
 160         int len;
 161         const char *arg;
 162
 163         if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 164                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 165         len = reader->pktlen;
 166
 167         if (!strcmp(reader->line, "NAK"))
 168                 return NAK;
 169         if (skip_prefix(reader->line, "ACK ", &arg)) {
 170                 const char *p;
 171                 if (!parse_oid_hex(arg, result_oid, &p)) {
 172                         len -= p - reader->line;
 173                         if (len < 1)
 174                                 return ACK;
 175                         if (strstr(p, "continue"))
 176                                 return ACK_continue;
 177                         if (strstr(p, "common"))
 178                                 return ACK_common;
 179                         if (strstr(p, "ready"))
 180                                 return ACK_ready;
 181                         return ACK;
 182                 }
 183         }
 184         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
 185 }
 186
 187 static void send_request(struct fetch_pack_args *args,
 188                          int fd, struct strbuf *buf)
 189 {
 190         if (args->stateless_rpc) {
 191                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 192                 packet_flush(fd);
 193         } else {
 194                 if (write_in_full(fd, buf->buf, buf->len) < 0)
 195                         die_errno(_("unable to write to remote"));
 196         }
 197 }
 198
 199 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 200                                         struct object *obj)
 201 {
 202         rev_list_insert_ref(negotiator, NULL, &obj->oid);
 203 }
 204
 205 #define INITIAL_FLUSH 16
 206 #define PIPESAFE_FLUSH 32
 207 #define LARGE_FLUSH 16384
 208
 209 static int next_flush(int stateless_rpc, int count)
 210 {
 211         if (stateless_rpc) {
 212                 if (count < LARGE_FLUSH)
 213                         count <<= 1;
 214                 else
 215                         count = count * 11 / 10;
 216         } else {
 217                 if (count < PIPESAFE_FLUSH)
 218                         count <<= 1;
 219                 else
 220                         count += PIPESAFE_FLUSH;
 221         }
 222         return count;
 223 }
 224
 225 static void mark_tips(struct fetch_negotiator *negotiator,
 226                       const struct oid_array *negotiation_tips)
 227 {
 228         int i;
 229
 230         if (!negotiation_tips) {
 231                 for_each_ref(rev_list_insert_ref_oid, negotiator);
 232                 return;
 233         }
 234
 235         for (i = 0; i < negotiation_tips->nr; i++)
 236                 rev_list_insert_ref(negotiator, NULL,
 237                                     &negotiation_tips->oid[i]);
 238         return;
 239 }
 240
 241 static int find_common(struct fetch_negotiator *negotiator,
 242                        struct fetch_pack_args *args,
 243                        int fd[2], struct object_id *result_oid,
 244                        struct ref *refs)
 245 {
 246         int fetching;
 247         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 248         const struct object_id *oid;
 249         unsigned in_vain = 0;
 250         int got_continue = 0;
 251         int got_ready = 0;
 252         struct strbuf req_buf = STRBUF_INIT;
 253         size_t state_len = 0;
 254         struct packet_reader reader;
 255
 256         if (args->stateless_rpc && multi_ack == 1)
 257                 die(_("--stateless-rpc requires multi_ack_detailed"));
 258
 259         packet_reader_init(&reader, fd[0], NULL, 0,
 260                            PACKET_READ_CHOMP_NEWLINE |
 261                            PACKET_READ_DIE_ON_ERR_PACKET);
 262
 263         if (!args->no_dependents) {
 264                 mark_tips(negotiator, args->negotiation_tips);
 265                 for_each_cached_alternate(negotiator, insert_one_alternate_object);
 266         }
 267
 268         fetching = 0;
 269         for ( ; refs ; refs = refs->next) {
 270                 struct object_id *remote = &refs->old_oid;
 271                 const char *remote_hex;
 272                 struct object *o;
 273
 274                 /*
 275                  * If that object is complete (i.e. it is an ancestor of a
 276                  * local ref), we tell them we have it but do not have to
 277                  * tell them about its ancestors, which they already know
 278                  * about.
 279                  *
 280                  * We use lookup_object here because we are only
 281                  * interested in the case we *know* the object is
 282                  * reachable and we have already scanned it.
 283                  *
 284                  * Do this only if args->no_dependents is false (if it is true,
 285                  * we cannot trust the object flags).
 286                  */
 287                 if (!args->no_dependents &&
 288                     ((o = lookup_object(the_repository, remote)) != NULL) &&
 289                                 (o->flags & COMPLETE)) {
 290                         continue;
 291                 }
 292
 293                 remote_hex = oid_to_hex(remote);
 294                 if (!fetching) {
 295                         struct strbuf c = STRBUF_INIT;
 296                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 297                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 298                         if (no_done)            strbuf_addstr(&c, " no-done");
 299                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 300                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 301                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 302                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 303                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 304                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 305                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 306                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 307                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 308                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 309                                                             git_user_agent_sanitized());
 310                         if (args->filter_options.choice)
 311                                 strbuf_addstr(&c, " filter");
 312                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 313                         strbuf_release(&c);
 314                 } else
 315                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 316                 fetching++;
 317         }
 318
 319         if (!fetching) {
 320                 strbuf_release(&req_buf);
 321                 packet_flush(fd[1]);
 322                 return 1;
 323         }
 324
 325         if (is_repository_shallow(the_repository))
 326                 write_shallow_commits(&req_buf, 1, NULL);
 327         if (args->depth > 0)
 328                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 329         if (args->deepen_since) {
 330                 timestamp_t max_age = approxidate(args->deepen_since);
 331                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 332         }
 333         if (args->deepen_not) {
 334                 int i;
 335                 for (i = 0; i < args->deepen_not->nr; i++) {
 336                         struct string_list_item *s = args->deepen_not->items + i;
 337                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 338                 }
 339         }
 340         if (server_supports_filtering && args->filter_options.choice) {
 341                 const char *spec =
 342                         expand_list_objects_filter_spec(&args->filter_options);
 343                 packet_buf_write(&req_buf, "filter %s", spec);
 344         }
 345         packet_buf_flush(&req_buf);
 346         state_len = req_buf.len;
 347
 348         if (args->deepen) {
 349                 const char *arg;
 350                 struct object_id oid;
 351
 352                 send_request(args, fd[1], &req_buf);
 353                 while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
 354                         if (skip_prefix(reader.line, "shallow ", &arg)) {
 355                                 if (get_oid_hex(arg, &oid))
 356                                         die(_("invalid shallow line: %s"), reader.line);
 357                                 register_shallow(the_repository, &oid);
 358                                 continue;
 359                         }
 360                         if (skip_prefix(reader.line, "unshallow ", &arg)) {
 361                                 if (get_oid_hex(arg, &oid))
 362                                         die(_("invalid unshallow line: %s"), reader.line);
 363                                 if (!lookup_object(the_repository, &oid))
 364                                         die(_("object not found: %s"), reader.line);
 365                                 /* make sure that it is parsed as shallow */
 366                                 if (!parse_object(the_repository, &oid))
 367                                         die(_("error in object: %s"), reader.line);
 368                                 if (unregister_shallow(&oid))
 369                                         die(_("no shallow found: %s"), reader.line);
 370                                 continue;
 371                         }
 372                         die(_("expected shallow/unshallow, got %s"), reader.line);
 373                 }
 374         } else if (!args->stateless_rpc)
 375                 send_request(args, fd[1], &req_buf);
 376
 377         if (!args->stateless_rpc) {
 378                 /* If we aren't using the stateless-rpc interface
 379                  * we don't need to retain the headers.
 380                  */
 381                 strbuf_setlen(&req_buf, 0);
 382                 state_len = 0;
 383         }
 384
 385         trace2_region_enter("fetch-pack", "negotiation_v0_v1", the_repository);
 386         flushes = 0;
 387         retval = -1;
 388         if (args->no_dependents)
 389                 goto done;
 390         while ((oid = negotiator->next(negotiator))) {
 391                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 392                 print_verbose(args, "have %s", oid_to_hex(oid));
 393                 in_vain++;
 394                 if (flush_at <= ++count) {
 395                         int ack;
 396
 397                         packet_buf_flush(&req_buf);
 398                         send_request(args, fd[1], &req_buf);
 399                         strbuf_setlen(&req_buf, state_len);
 400                         flushes++;
 401                         flush_at = next_flush(args->stateless_rpc, count);
 402
 403                         /*
 404                          * We keep one window "ahead" of the other side, and
 405                          * will wait for an ACK only on the next one
 406                          */
 407                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 408                                 continue;
 409
 410                         consume_shallow_list(args, &reader);
 411                         do {
 412                                 ack = get_ack(&reader, result_oid);
 413                                 if (ack)
 414                                         print_verbose(args, _("got %s %d %s"), "ack",
 415                                                       ack, oid_to_hex(result_oid));
 416                                 switch (ack) {
 417                                 case ACK:
 418                                         flushes = 0;
 419                                         multi_ack = 0;
 420                                         retval = 0;
 421                                         goto done;
 422                                 case ACK_common:
 423                                 case ACK_ready:
 424                                 case ACK_continue: {
 425                                         struct commit *commit =
 426                                                 lookup_commit(the_repository,
 427                                                               result_oid);
 428                                         int was_common;
 429
 430                                         if (!commit)
 431                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 432                                         was_common = negotiator->ack(negotiator, commit);
 433                                         if (args->stateless_rpc
 434                                          && ack == ACK_common
 435                                          && !was_common) {
 436                                                 /* We need to replay the have for this object
 437                                                  * on the next RPC request so the peer knows
 438                                                  * it is in common with us.
 439                                                  */
 440                                                 const char *hex = oid_to_hex(result_oid);
 441                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 442                                                 state_len = req_buf.len;
 443                                                 /*
 444                                                  * Reset in_vain because an ack
 445                                                  * for this commit has not been
 446                                                  * seen.
 447                                                  */
 448                                                 in_vain = 0;
 449                                         } else if (!args->stateless_rpc
 450                                                    || ack != ACK_common)
 451                                                 in_vain = 0;
 452                                         retval = 0;
 453                                         got_continue = 1;
 454                                         if (ack == ACK_ready)
 455                                                 got_ready = 1;
 456                                         break;
 457                                         }
 458                                 }
 459                         } while (ack);
 460                         flushes--;
 461                         if (got_continue && MAX_IN_VAIN < in_vain) {
 462                                 print_verbose(args, _("giving up"));
 463                                 break; /* give up */
 464                         }
 465                         if (got_ready)
 466                                 break;
 467                 }
 468         }
 469 done:
 470         trace2_region_leave("fetch-pack", "negotiation_v0_v1", the_repository);
 471         if (!got_ready || !no_done) {
 472                 packet_buf_write(&req_buf, "done\n");
 473                 send_request(args, fd[1], &req_buf);
 474         }
 475         print_verbose(args, _("done"));
 476         if (retval != 0) {
 477                 multi_ack = 0;
 478                 flushes++;
 479         }
 480         strbuf_release(&req_buf);
 481
 482         if (!got_ready || !no_done)
 483                 consume_shallow_list(args, &reader);
 484         while (flushes || multi_ack) {
 485                 int ack = get_ack(&reader, result_oid);
 486                 if (ack) {
 487                         print_verbose(args, _("got %s (%d) %s"), "ack",
 488                                       ack, oid_to_hex(result_oid));
 489                         if (ack == ACK)
 490                                 return 0;
 491                         multi_ack = 1;
 492                         continue;
 493                 }
 494                 flushes--;
 495         }
 496         /* it is no error to fetch into a completely empty repo */
 497         return count ? retval : 0;
 498 }
 499
 500 static struct commit_list *complete;
 501
 502 static int mark_complete(const struct object_id *oid)
 503 {
 504         struct object *o = parse_object(the_repository, oid);
 505
 506         while (o && o->type == OBJ_TAG) {
 507                 struct tag *t = (struct tag *) o;
 508                 if (!t->tagged)
 509                         break; /* broken repository */
 510                 o->flags |= COMPLETE;
 511                 o = parse_object(the_repository, &t->tagged->oid);
 512         }
 513         if (o && o->type == OBJ_COMMIT) {
 514                 struct commit *commit = (struct commit *)o;
 515                 if (!(commit->object.flags & COMPLETE)) {
 516                         commit->object.flags |= COMPLETE;
 517                         commit_list_insert(commit, &complete);
 518                 }
 519         }
 520         return 0;
 521 }
 522
 523 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 524                              int flag, void *cb_data)
 525 {
 526         return mark_complete(oid);
 527 }
 528
 529 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 530                                          timestamp_t cutoff)
 531 {
 532         while (complete && cutoff <= complete->item->date) {
 533                 print_verbose(args, _("Marking %s as complete"),
 534                               oid_to_hex(&complete->item->object.oid));
 535                 pop_most_recent_commit(&complete, COMPLETE);
 536         }
 537 }
 538
 539 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 540 {
 541         for (; refs; refs = refs->next)
 542                 oidset_insert(oids, &refs->old_oid);
 543 }
 544
 545 static int is_unmatched_ref(const struct ref *ref)
 546 {
 547         struct object_id oid;
 548         const char *p;
 549         return  ref->match_status == REF_NOT_MATCHED &&
 550                 !parse_oid_hex(ref->name, &oid, &p) &&
 551                 *p == '\0' &&
 552                 oideq(&oid, &ref->old_oid);
 553 }
 554
 555 static void filter_refs(struct fetch_pack_args *args,
 556                         struct ref **refs,
 557                         struct ref **sought, int nr_sought)
 558 {
 559         struct ref *newlist = NULL;
 560         struct ref **newtail = &newlist;
 561         struct ref *unmatched = NULL;
 562         struct ref *ref, *next;
 563         struct oidset tip_oids = OIDSET_INIT;
 564         int i;
 565         int strict = !(allow_unadvertised_object_request &
 566                        (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 567
 568         i = 0;
 569         for (ref = *refs; ref; ref = next) {
 570                 int keep = 0;
 571                 next = ref->next;
 572
 573                 if (starts_with(ref->name, "refs/") &&
 574                     check_refname_format(ref->name, 0)) {
 575                         /*
 576                          * trash or a peeled value; do not even add it to
 577                          * unmatched list
 578                          */
 579                         free_one_ref(ref);
 580                         continue;
 581                 } else {
 582                         while (i < nr_sought) {
 583                                 int cmp = strcmp(ref->name, sought[i]->name);
 584                                 if (cmp < 0)
 585                                         break; /* definitely do not have it */
 586                                 else if (cmp == 0) {
 587                                         keep = 1; /* definitely have it */
 588                                         sought[i]->match_status = REF_MATCHED;
 589                                 }
 590                                 i++;
 591                         }
 592
 593                         if (!keep && args->fetch_all &&
 594                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 595                                 keep = 1;
 596                 }
 597
 598                 if (keep) {
 599                         *newtail = ref;
 600                         ref->next = NULL;
 601                         newtail = &ref->next;
 602                 } else {
 603                         ref->next = unmatched;
 604                         unmatched = ref;
 605                 }
 606         }
 607
 608         if (strict) {
 609                 for (i = 0; i < nr_sought; i++) {
 610                         ref = sought[i];
 611                         if (!is_unmatched_ref(ref))
 612                                 continue;
 613
 614                         add_refs_to_oidset(&tip_oids, unmatched);
 615                         add_refs_to_oidset(&tip_oids, newlist);
 616                         break;
 617                 }
 618         }
 619
 620         /* Append unmatched requests to the list */
 621         for (i = 0; i < nr_sought; i++) {
 622                 ref = sought[i];
 623                 if (!is_unmatched_ref(ref))
 624                         continue;
 625
 626                 if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 627                         ref->match_status = REF_MATCHED;
 628                         *newtail = copy_ref(ref);
 629                         newtail = &(*newtail)->next;
 630                 } else {
 631                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 632                 }
 633         }
 634
 635         oidset_clear(&tip_oids);
 636         free_refs(unmatched);
 637
 638         *refs = newlist;
 639 }
 640
 641 static void mark_alternate_complete(struct fetch_negotiator *unused,
 642                                     struct object *obj)
 643 {
 644         mark_complete(&obj->oid);
 645 }
 646
 647 struct loose_object_iter {
 648         struct oidset *loose_object_set;
 649         struct ref *refs;
 650 };
 651
 652 /*
 653  * Mark recent commits available locally and reachable from a local ref as
 654  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 655  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 656  * thus do not need COMMON_REF marks).
 657  *
 658  * The cutoff time for recency is determined by this heuristic: it is the
 659  * earliest commit time of the objects in refs that are commits and that we know
 660  * the commit time of.
 661  */
 662 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 663                                          struct fetch_pack_args *args,
 664                                          struct ref **refs)
 665 {
 666         struct ref *ref;
 667         int old_save_commit_buffer = save_commit_buffer;
 668         timestamp_t cutoff = 0;
 669
 670         save_commit_buffer = 0;
 671
 672         trace2_region_enter("fetch-pack", "parse_remote_refs_and_find_cutoff", NULL);
 673         for (ref = *refs; ref; ref = ref->next) {
 674                 struct object *o;
 675
 676                 if (!has_object_file_with_flags(&ref->old_oid,
 677                                                 OBJECT_INFO_QUICK))
 678                         continue;
 679                 o = parse_object(the_repository, &ref->old_oid);
 680                 if (!o)
 681                         continue;
 682
 683                 /*
 684                  * We already have it -- which may mean that we were
 685                  * in sync with the other side at some time after
 686                  * that (it is OK if we guess wrong here).
 687                  */
 688                 if (o->type == OBJ_COMMIT) {
 689                         struct commit *commit = (struct commit *)o;
 690                         if (!cutoff || cutoff < commit->date)
 691                                 cutoff = commit->date;
 692                 }
 693         }
 694         trace2_region_leave("fetch-pack", "parse_remote_refs_and_find_cutoff", NULL);
 695
 696         /*
 697          * This block marks all local refs as COMPLETE, and then recursively marks all
 698          * parents of those refs as COMPLETE.
 699          */
 700         trace2_region_enter("fetch-pack", "mark_complete_local_refs", NULL);
 701         if (!args->deepen) {
 702                 for_each_ref(mark_complete_oid, NULL);
 703                 for_each_cached_alternate(NULL, mark_alternate_complete);
 704                 commit_list_sort_by_date(&complete);
 705                 if (cutoff)
 706                         mark_recent_complete_commits(args, cutoff);
 707         }
 708         trace2_region_leave("fetch-pack", "mark_complete_local_refs", NULL);
 709
 710         /*
 711          * Mark all complete remote refs as common refs.
 712          * Don't mark them common yet; the server has to be told so first.
 713          */
 714         trace2_region_enter("fetch-pack", "mark_common_remote_refs", NULL);
 715         for (ref = *refs; ref; ref = ref->next) {
 716                 struct object *o = deref_tag(the_repository,
 717                                              lookup_object(the_repository,
 718                                              &ref->old_oid),
 719                                              NULL, 0);
 720
 721                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 722                         continue;
 723
 724                 negotiator->known_common(negotiator,
 725                                          (struct commit *)o);
 726         }
 727         trace2_region_leave("fetch-pack", "mark_common_remote_refs", NULL);
 728
 729         save_commit_buffer = old_save_commit_buffer;
 730 }
 731
 732 /*
 733  * Returns 1 if every object pointed to by the given remote refs is available
 734  * locally and reachable from a local ref, and 0 otherwise.
 735  */
 736 static int everything_local(struct fetch_pack_args *args,
 737                             struct ref **refs)
 738 {
 739         struct ref *ref;
 740         int retval;
 741
 742         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 743                 const struct object_id *remote = &ref->old_oid;
 744                 struct object *o;
 745
 746                 o = lookup_object(the_repository, remote);
 747                 if (!o || !(o->flags & COMPLETE)) {
 748                         retval = 0;
 749                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 750                                       ref->name);
 751                         continue;
 752                 }
 753                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 754                               ref->name);
 755         }
 756
 757         return retval;
 758 }
 759
 760 static int sideband_demux(int in, int out, void *data)
 761 {
 762         int *xd = data;
 763         int ret;
 764
 765         ret = recv_sideband("fetch-pack", xd[0], out);
 766         close(out);
 767         return ret;
 768 }
 769
 770 static int get_pack(struct fetch_pack_args *args,
 771                     int xd[2], char **pack_lockfile)
 772 {
 773         struct async demux;
 774         int do_keep = args->keep_pack;
 775         const char *cmd_name;
 776         struct pack_header header;
 777         int pass_header = 0;
 778         struct child_process cmd = CHILD_PROCESS_INIT;
 779         int ret;
 780
 781         memset(&demux, 0, sizeof(demux));
 782         if (use_sideband) {
 783                 /* xd[] is talking with upload-pack; subprocess reads from
 784                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 785                  * through demux->out.
 786                  */
 787                 demux.proc = sideband_demux;
 788                 demux.data = xd;
 789                 demux.out = -1;
 790                 demux.isolate_sigpipe = 1;
 791                 if (start_async(&demux))
 792                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 793         }
 794         else
 795                 demux.out = xd[0];
 796
 797         if (!args->keep_pack && unpack_limit) {
 798
 799                 if (read_pack_header(demux.out, &header))
 800                         die(_("protocol error: bad pack header"));
 801                 pass_header = 1;
 802                 if (ntohl(header.hdr_entries) < unpack_limit)
 803                         do_keep = 0;
 804                 else
 805                         do_keep = 1;
 806         }
 807
 808         if (alternate_shallow_file) {
 809                 argv_array_push(&cmd.args, "--shallow-file");
 810                 argv_array_push(&cmd.args, alternate_shallow_file);
 811         }
 812
 813         if (do_keep || args->from_promisor) {
 814                 if (pack_lockfile)
 815                         cmd.out = -1;
 816                 cmd_name = "index-pack";
 817                 argv_array_push(&cmd.args, cmd_name);
 818                 argv_array_push(&cmd.args, "--stdin");
 819                 if (!args->quiet && !args->no_progress)
 820                         argv_array_push(&cmd.args, "-v");
 821                 if (args->use_thin_pack)
 822                         argv_array_push(&cmd.args, "--fix-thin");
 823                 if (do_keep && (args->lock_pack || unpack_limit)) {
 824                         char hostname[HOST_NAME_MAX + 1];
 825                         if (xgethostname(hostname, sizeof(hostname)))
 826                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 827                         argv_array_pushf(&cmd.args,
 828                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 829                                         (uintmax_t)getpid(), hostname);
 830                 }
 831                 if (args->check_self_contained_and_connected)
 832                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 833                 if (args->from_promisor)
 834                         argv_array_push(&cmd.args, "--promisor");
 835         }
 836         else {
 837                 cmd_name = "unpack-objects";
 838                 argv_array_push(&cmd.args, cmd_name);
 839                 if (args->quiet || args->no_progress)
 840                         argv_array_push(&cmd.args, "-q");
 841                 args->check_self_contained_and_connected = 0;
 842         }
 843
 844         if (pass_header)
 845                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 846                                  ntohl(header.hdr_version),
 847                                  ntohl(header.hdr_entries));
 848         if (fetch_fsck_objects >= 0
 849             ? fetch_fsck_objects
 850             : transfer_fsck_objects >= 0
 851             ? transfer_fsck_objects
 852             : 0) {
 853                 if (args->from_promisor)
 854                         /*
 855                          * We cannot use --strict in index-pack because it
 856                          * checks both broken objects and links, but we only
 857                          * want to check for broken objects.
 858                          */
 859                         argv_array_push(&cmd.args, "--fsck-objects");
 860                 else
 861                         argv_array_pushf(&cmd.args, "--strict%s",
 862                                          fsck_msg_types.buf);
 863         }
 864
 865         cmd.in = demux.out;
 866         cmd.git_cmd = 1;
 867         if (start_command(&cmd))
 868                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 869         if (do_keep && pack_lockfile) {
 870                 *pack_lockfile = index_pack_lockfile(cmd.out);
 871                 close(cmd.out);
 872         }
 873
 874         if (!use_sideband)
 875                 /* Closed by start_command() */
 876                 xd[0] = -1;
 877
 878         ret = finish_command(&cmd);
 879         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 880                 args->self_contained_and_connected =
 881                         args->check_self_contained_and_connected &&
 882                         ret == 0;
 883         else
 884                 die(_("%s failed"), cmd_name);
 885         if (use_sideband && finish_async(&demux))
 886                 die(_("error in sideband demultiplexer"));
 887         return 0;
 888 }
 889
 890 static int cmp_ref_by_name(const void *a_, const void *b_)
 891 {
 892         const struct ref *a = *((const struct ref **)a_);
 893         const struct ref *b = *((const struct ref **)b_);
 894         return strcmp(a->name, b->name);
 895 }
 896
 897 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 898                                  int fd[2],
 899                                  const struct ref *orig_ref,
 900                                  struct ref **sought, int nr_sought,
 901                                  struct shallow_info *si,
 902                                  char **pack_lockfile)
 903 {
 904         struct repository *r = the_repository;
 905         struct ref *ref = copy_ref_list(orig_ref);
 906         struct object_id oid;
 907         const char *agent_feature;
 908         int agent_len;
 909         struct fetch_negotiator negotiator;
 910         fetch_negotiator_init(r, &negotiator);
 911
 912         sort_ref_list(&ref, ref_compare_name);
 913         QSORT(sought, nr_sought, cmp_ref_by_name);
 914
 915         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 916                 agent_supported = 1;
 917                 if (agent_len)
 918                         print_verbose(args, _("Server version is %.*s"),
 919                                       agent_len, agent_feature);
 920         }
 921
 922         if (server_supports("shallow"))
 923                 print_verbose(args, _("Server supports %s"), "shallow");
 924         else if (args->depth > 0 || is_repository_shallow(r))
 925                 die(_("Server does not support shallow clients"));
 926         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 927                 args->deepen = 1;
 928         if (server_supports("multi_ack_detailed")) {
 929                 print_verbose(args, _("Server supports %s"), "multi_ack_detailed");
 930                 multi_ack = 2;
 931                 if (server_supports("no-done")) {
 932                         print_verbose(args, _("Server supports %s"), "no-done");
 933                         if (args->stateless_rpc)
 934                                 no_done = 1;
 935                 }
 936         }
 937         else if (server_supports("multi_ack")) {
 938                 print_verbose(args, _("Server supports %s"), "multi_ack");
 939                 multi_ack = 1;
 940         }
 941         if (server_supports("side-band-64k")) {
 942                 print_verbose(args, _("Server supports %s"), "side-band-64k");
 943                 use_sideband = 2;
 944         }
 945         else if (server_supports("side-band")) {
 946                 print_verbose(args, _("Server supports %s"), "side-band");
 947                 use_sideband = 1;
 948         }
 949         if (server_supports("allow-tip-sha1-in-want")) {
 950                 print_verbose(args, _("Server supports %s"), "allow-tip-sha1-in-want");
 951                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 952         }
 953         if (server_supports("allow-reachable-sha1-in-want")) {
 954                 print_verbose(args, _("Server supports %s"), "allow-reachable-sha1-in-want");
 955                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 956         }
 957         if (server_supports("thin-pack"))
 958                 print_verbose(args, _("Server supports %s"), "thin-pack");
 959         else
 960                 args->use_thin_pack = 0;
 961         if (server_supports("no-progress"))
 962                 print_verbose(args, _("Server supports %s"), "no-progress");
 963         else
 964                 args->no_progress = 0;
 965         if (server_supports("include-tag"))
 966                 print_verbose(args, _("Server supports %s"), "include-tag");
 967         else
 968                 args->include_tag = 0;
 969         if (server_supports("ofs-delta"))
 970                 print_verbose(args, _("Server supports %s"), "ofs-delta");
 971         else
 972                 prefer_ofs_delta = 0;
 973
 974         if (server_supports("filter")) {
 975                 server_supports_filtering = 1;
 976                 print_verbose(args, _("Server supports %s"), "filter");
 977         } else if (args->filter_options.choice) {
 978                 warning("filtering not recognized by server, ignoring");
 979         }
 980
 981         if (server_supports("deepen-since")) {
 982                 print_verbose(args, _("Server supports %s"), "deepen-since");
 983                 deepen_since_ok = 1;
 984         } else if (args->deepen_since)
 985                 die(_("Server does not support --shallow-since"));
 986         if (server_supports("deepen-not")) {
 987                 print_verbose(args, _("Server supports %s"), "deepen-not");
 988                 deepen_not_ok = 1;
 989         } else if (args->deepen_not)
 990                 die(_("Server does not support --shallow-exclude"));
 991         if (server_supports("deepen-relative"))
 992                 print_verbose(args, _("Server supports %s"), "deepen-relative");
 993         else if (args->deepen_relative)
 994                 die(_("Server does not support --deepen"));
 995
 996         if (!args->no_dependents) {
 997                 mark_complete_and_common_ref(&negotiator, args, &ref);
 998                 filter_refs(args, &ref, sought, nr_sought);
 999                 if (everything_local(args, &ref)) {
1000                         packet_flush(fd[1]);
1001                         goto all_done;
1002                 }
1003         } else {
1004                 filter_refs(args, &ref, sought, nr_sought);
1005         }
1006         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
1007                 if (!args->keep_pack)
1008                         /* When cloning, it is not unusual to have
1009                          * no common commit.
1010                          */
1011                         warning(_("no common commits"));
1012
1013         if (args->stateless_rpc)
1014                 packet_flush(fd[1]);
1015         if (args->deepen)
1016                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1017                                         NULL);
1018         else if (si->nr_ours || si->nr_theirs)
1019                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
1020         else
1021                 alternate_shallow_file = NULL;
1022         if (get_pack(args, fd, pack_lockfile))
1023                 die(_("git fetch-pack: fetch failed."));
1024
1025  all_done:
1026         negotiator.release(&negotiator);
1027         return ref;
1028 }
1029
1030 static void add_shallow_requests(struct strbuf *req_buf,
1031                                  const struct fetch_pack_args *args)
1032 {
1033         if (is_repository_shallow(the_repository))
1034                 write_shallow_commits(req_buf, 1, NULL);
1035         if (args->depth > 0)
1036                 packet_buf_write(req_buf, "deepen %d", args->depth);
1037         if (args->deepen_since) {
1038                 timestamp_t max_age = approxidate(args->deepen_since);
1039                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1040         }
1041         if (args->deepen_not) {
1042                 int i;
1043                 for (i = 0; i < args->deepen_not->nr; i++) {
1044                         struct string_list_item *s = args->deepen_not->items + i;
1045                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1046                 }
1047         }
1048         if (args->deepen_relative)
1049                 packet_buf_write(req_buf, "deepen-relative\n");
1050 }
1051
1052 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1053 {
1054         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1055
1056         for ( ; wants ; wants = wants->next) {
1057                 const struct object_id *remote = &wants->old_oid;
1058                 struct object *o;
1059
1060                 /*
1061                  * If that object is complete (i.e. it is an ancestor of a
1062                  * local ref), we tell them we have it but do not have to
1063                  * tell them about its ancestors, which they already know
1064                  * about.
1065                  *
1066                  * We use lookup_object here because we are only
1067                  * interested in the case we *know* the object is
1068                  * reachable and we have already scanned it.
1069                  *
1070                  * Do this only if args->no_dependents is false (if it is true,
1071                  * we cannot trust the object flags).
1072                  */
1073                 if (!no_dependents &&
1074                     ((o = lookup_object(the_repository, remote)) != NULL) &&
1075                     (o->flags & COMPLETE)) {
1076                         continue;
1077                 }
1078
1079                 if (!use_ref_in_want || wants->exact_oid)
1080                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1081                 else
1082                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1083         }
1084 }
1085
1086 static void add_common(struct strbuf *req_buf, struct oidset *common)
1087 {
1088         struct oidset_iter iter;
1089         const struct object_id *oid;
1090         oidset_iter_init(common, &iter);
1091
1092         while ((oid = oidset_iter_next(&iter))) {
1093                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1094         }
1095 }
1096
1097 static int add_haves(struct fetch_negotiator *negotiator,
1098                      struct strbuf *req_buf,
1099                      int *haves_to_send, int *in_vain)
1100 {
1101         int ret = 0;
1102         int haves_added = 0;
1103         const struct object_id *oid;
1104
1105         while ((oid = negotiator->next(negotiator))) {
1106                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1107                 if (++haves_added >= *haves_to_send)
1108                         break;
1109         }
1110
1111         *in_vain += haves_added;
1112         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1113                 /* Send Done */
1114                 packet_buf_write(req_buf, "done\n");
1115                 ret = 1;
1116         }
1117
1118         /* Increase haves to send on next round */
1119         *haves_to_send = next_flush(1, *haves_to_send);
1120
1121         return ret;
1122 }
1123
1124 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1125                               struct fetch_pack_args *args,
1126                               const struct ref *wants, struct oidset *common,
1127                               int *haves_to_send, int *in_vain,
1128                               int sideband_all)
1129 {
1130         int ret = 0;
1131         struct strbuf req_buf = STRBUF_INIT;
1132
1133         if (server_supports_v2("fetch", 1))
1134                 packet_buf_write(&req_buf, "command=fetch");
1135         if (server_supports_v2("agent", 0))
1136                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1137         if (args->server_options && args->server_options->nr &&
1138             server_supports_v2("server-option", 1)) {
1139                 int i;
1140                 for (i = 0; i < args->server_options->nr; i++)
1141                         packet_buf_write(&req_buf, "server-option=%s",
1142                                          args->server_options->items[i].string);
1143         }
1144
1145         packet_buf_delim(&req_buf);
1146         if (args->use_thin_pack)
1147                 packet_buf_write(&req_buf, "thin-pack");
1148         if (args->no_progress)
1149                 packet_buf_write(&req_buf, "no-progress");
1150         if (args->include_tag)
1151                 packet_buf_write(&req_buf, "include-tag");
1152         if (prefer_ofs_delta)
1153                 packet_buf_write(&req_buf, "ofs-delta");
1154         if (sideband_all)
1155                 packet_buf_write(&req_buf, "sideband-all");
1156
1157         /* Add shallow-info and deepen request */
1158         if (server_supports_feature("fetch", "shallow", 0))
1159                 add_shallow_requests(&req_buf, args);
1160         else if (is_repository_shallow(the_repository) || args->deepen)
1161                 die(_("Server does not support shallow requests"));
1162
1163         /* Add filter */
1164         if (server_supports_feature("fetch", "filter", 0) &&
1165             args->filter_options.choice) {
1166                 const char *spec =
1167                         expand_list_objects_filter_spec(&args->filter_options);
1168                 print_verbose(args, _("Server supports filter"));
1169                 packet_buf_write(&req_buf, "filter %s", spec);
1170         } else if (args->filter_options.choice) {
1171                 warning("filtering not recognized by server, ignoring");
1172         }
1173
1174         /* add wants */
1175         add_wants(args->no_dependents, wants, &req_buf);
1176
1177         if (args->no_dependents) {
1178                 packet_buf_write(&req_buf, "done");
1179                 ret = 1;
1180         } else {
1181                 /* Add all of the common commits we've found in previous rounds */
1182                 add_common(&req_buf, common);
1183
1184                 /* Add initial haves */
1185                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1186         }
1187
1188         /* Send request */
1189         packet_buf_flush(&req_buf);
1190         if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
1191                 die_errno(_("unable to write request to remote"));
1192
1193         strbuf_release(&req_buf);
1194         return ret;
1195 }
1196
1197 /*
1198  * Processes a section header in a server's response and checks if it matches
1199  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1200  * not consumed); if 0, the line will be consumed and the function will die if
1201  * the section header doesn't match what was expected.
1202  */
1203 static int process_section_header(struct packet_reader *reader,
1204                                   const char *section, int peek)
1205 {
1206         int ret;
1207
1208         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1209                 die(_("error reading section header '%s'"), section);
1210
1211         ret = !strcmp(reader->line, section);
1212
1213         if (!peek) {
1214                 if (!ret)
1215                         die(_("expected '%s', received '%s'"),
1216                             section, reader->line);
1217                 packet_reader_read(reader);
1218         }
1219
1220         return ret;
1221 }
1222
1223 static int process_acks(struct fetch_negotiator *negotiator,
1224                         struct packet_reader *reader,
1225                         struct oidset *common)
1226 {
1227         /* received */
1228         int received_ready = 0;
1229         int received_ack = 0;
1230
1231         process_section_header(reader, "acknowledgments", 0);
1232         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1233                 const char *arg;
1234
1235                 if (!strcmp(reader->line, "NAK"))
1236                         continue;
1237
1238                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1239                         struct object_id oid;
1240                         if (!get_oid_hex(arg, &oid)) {
1241                                 struct commit *commit;
1242                                 oidset_insert(common, &oid);
1243                                 commit = lookup_commit(the_repository, &oid);
1244                                 negotiator->ack(negotiator, commit);
1245                         }
1246                         continue;
1247                 }
1248
1249                 if (!strcmp(reader->line, "ready")) {
1250                         received_ready = 1;
1251                         continue;
1252                 }
1253
1254                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1255         }
1256
1257         if (reader->status != PACKET_READ_FLUSH &&
1258             reader->status != PACKET_READ_DELIM)
1259                 die(_("error processing acks: %d"), reader->status);
1260
1261         /*
1262          * If an "acknowledgments" section is sent, a packfile is sent if and
1263          * only if "ready" was sent in this section. The other sections
1264          * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1265          * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1266          * otherwise.
1267          */
1268         if (received_ready && reader->status != PACKET_READ_DELIM)
1269                 die(_("expected packfile to be sent after 'ready'"));
1270         if (!received_ready && reader->status != PACKET_READ_FLUSH)
1271                 die(_("expected no other sections to be sent after no 'ready'"));
1272
1273         /* return 0 if no common, 1 if there are common, or 2 if ready */
1274         return received_ready ? 2 : (received_ack ? 1 : 0);
1275 }
1276
1277 static void receive_shallow_info(struct fetch_pack_args *args,
1278                                  struct packet_reader *reader,
1279                                  struct oid_array *shallows,
1280                                  struct shallow_info *si)
1281 {
1282         int unshallow_received = 0;
1283
1284         process_section_header(reader, "shallow-info", 0);
1285         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1286                 const char *arg;
1287                 struct object_id oid;
1288
1289                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1290                         if (get_oid_hex(arg, &oid))
1291                                 die(_("invalid shallow line: %s"), reader->line);
1292                         oid_array_append(shallows, &oid);
1293                         continue;
1294                 }
1295                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1296                         if (get_oid_hex(arg, &oid))
1297                                 die(_("invalid unshallow line: %s"), reader->line);
1298                         if (!lookup_object(the_repository, &oid))
1299                                 die(_("object not found: %s"), reader->line);
1300                         /* make sure that it is parsed as shallow */
1301                         if (!parse_object(the_repository, &oid))
1302                                 die(_("error in object: %s"), reader->line);
1303                         if (unregister_shallow(&oid))
1304                                 die(_("no shallow found: %s"), reader->line);
1305                         unshallow_received = 1;
1306                         continue;
1307                 }
1308                 die(_("expected shallow/unshallow, got %s"), reader->line);
1309         }
1310
1311         if (reader->status != PACKET_READ_FLUSH &&
1312             reader->status != PACKET_READ_DELIM)
1313                 die(_("error processing shallow info: %d"), reader->status);
1314
1315         if (args->deepen || unshallow_received) {
1316                 /*
1317                  * Treat these as shallow lines caused by our depth settings.
1318                  * In v0, these lines cannot cause refs to be rejected; do the
1319                  * same.
1320                  */
1321                 int i;
1322
1323                 for (i = 0; i < shallows->nr; i++)
1324                         register_shallow(the_repository, &shallows->oid[i]);
1325                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1326                                         NULL);
1327                 args->deepen = 1;
1328         } else if (shallows->nr) {
1329                 /*
1330                  * Treat these as shallow lines caused by the remote being
1331                  * shallow. In v0, remote refs that reach these objects are
1332                  * rejected (unless --update-shallow is set); do the same.
1333                  */
1334                 prepare_shallow_info(si, shallows);
1335                 if (si->nr_ours || si->nr_theirs)
1336                         alternate_shallow_file =
1337                                 setup_temporary_shallow(si->shallow);
1338                 else
1339                         alternate_shallow_file = NULL;
1340         } else {
1341                 alternate_shallow_file = NULL;
1342         }
1343 }
1344
1345 static int cmp_name_ref(const void *name, const void *ref)
1346 {
1347         return strcmp(name, (*(struct ref **)ref)->name);
1348 }
1349
1350 static void receive_wanted_refs(struct packet_reader *reader,
1351                                 struct ref **sought, int nr_sought)
1352 {
1353         process_section_header(reader, "wanted-refs", 0);
1354         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1355                 struct object_id oid;
1356                 const char *end;
1357                 struct ref **found;
1358
1359                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1360                         die(_("expected wanted-ref, got '%s'"), reader->line);
1361
1362                 found = bsearch(end, sought, nr_sought, sizeof(*sought),
1363                                 cmp_name_ref);
1364                 if (!found)
1365                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1366                 oidcpy(&(*found)->old_oid, &oid);
1367         }
1368
1369         if (reader->status != PACKET_READ_DELIM)
1370                 die(_("error processing wanted refs: %d"), reader->status);
1371 }
1372
1373 enum fetch_state {
1374         FETCH_CHECK_LOCAL = 0,
1375         FETCH_SEND_REQUEST,
1376         FETCH_PROCESS_ACKS,
1377         FETCH_GET_PACK,
1378         FETCH_DONE,
1379 };
1380
1381 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1382                                     int fd[2],
1383                                     const struct ref *orig_ref,
1384                                     struct ref **sought, int nr_sought,
1385                                     struct oid_array *shallows,
1386                                     struct shallow_info *si,
1387                                     char **pack_lockfile)
1388 {
1389         struct repository *r = the_repository;
1390         struct ref *ref = copy_ref_list(orig_ref);
1391         enum fetch_state state = FETCH_CHECK_LOCAL;
1392         struct oidset common = OIDSET_INIT;
1393         struct packet_reader reader;
1394         int in_vain = 0, negotiation_started = 0;
1395         int haves_to_send = INITIAL_FLUSH;
1396         struct fetch_negotiator negotiator;
1397         fetch_negotiator_init(r, &negotiator);
1398         packet_reader_init(&reader, fd[0], NULL, 0,
1399                            PACKET_READ_CHOMP_NEWLINE |
1400                            PACKET_READ_DIE_ON_ERR_PACKET);
1401         if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
1402             server_supports_feature("fetch", "sideband-all", 0)) {
1403                 reader.use_sideband = 1;
1404                 reader.me = "fetch-pack";
1405         }
1406
1407         while (state != FETCH_DONE) {
1408                 switch (state) {
1409                 case FETCH_CHECK_LOCAL:
1410                         sort_ref_list(&ref, ref_compare_name);
1411                         QSORT(sought, nr_sought, cmp_ref_by_name);
1412
1413                         /* v2 supports these by default */
1414                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1415                         use_sideband = 2;
1416                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1417                                 args->deepen = 1;
1418
1419                         /* Filter 'ref' by 'sought' and those that aren't local */
1420                         if (!args->no_dependents) {
1421                                 mark_complete_and_common_ref(&negotiator, args, &ref);
1422                                 filter_refs(args, &ref, sought, nr_sought);
1423                                 if (everything_local(args, &ref))
1424                                         state = FETCH_DONE;
1425                                 else
1426                                         state = FETCH_SEND_REQUEST;
1427
1428                                 mark_tips(&negotiator, args->negotiation_tips);
1429                                 for_each_cached_alternate(&negotiator,
1430                                                           insert_one_alternate_object);
1431                         } else {
1432                                 filter_refs(args, &ref, sought, nr_sought);
1433                                 state = FETCH_SEND_REQUEST;
1434                         }
1435                         break;
1436                 case FETCH_SEND_REQUEST:
1437                         if (!negotiation_started) {
1438                                 negotiation_started = 1;
1439                                 trace2_region_enter("fetch-pack",
1440                                                     "negotiation_v2",
1441                                                     the_repository);
1442                         }
1443                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1444                                                &common,
1445                                                &haves_to_send, &in_vain,
1446                                                reader.use_sideband))
1447                                 state = FETCH_GET_PACK;
1448                         else
1449                                 state = FETCH_PROCESS_ACKS;
1450                         break;
1451                 case FETCH_PROCESS_ACKS:
1452                         /* Process ACKs/NAKs */
1453                         switch (process_acks(&negotiator, &reader, &common)) {
1454                         case 2:
1455                                 state = FETCH_GET_PACK;
1456                                 break;
1457                         case 1:
1458                                 in_vain = 0;
1459                                 /* fallthrough */
1460                         default:
1461                                 state = FETCH_SEND_REQUEST;
1462                                 break;
1463                         }
1464                         break;
1465                 case FETCH_GET_PACK:
1466                         trace2_region_leave("fetch-pack",
1467                                             "negotiation_v2",
1468                                             the_repository);
1469                         /* Check for shallow-info section */
1470                         if (process_section_header(&reader, "shallow-info", 1))
1471                                 receive_shallow_info(args, &reader, shallows, si);
1472
1473                         if (process_section_header(&reader, "wanted-refs", 1))
1474                                 receive_wanted_refs(&reader, sought, nr_sought);
1475
1476                         /* get the pack */
1477                         process_section_header(&reader, "packfile", 0);
1478                         if (get_pack(args, fd, pack_lockfile))
1479                                 die(_("git fetch-pack: fetch failed."));
1480
1481                         state = FETCH_DONE;
1482                         break;
1483                 case FETCH_DONE:
1484                         continue;
1485                 }
1486         }
1487
1488         negotiator.release(&negotiator);
1489         oidset_clear(&common);
1490         return ref;
1491 }
1492
1493 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1494 {
1495         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1496                 const char *path;
1497
1498                 if (git_config_pathname(&path, var, value))
1499                         return 1;
1500                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1501                         fsck_msg_types.len ? ',' : '=', path);
1502                 free((char *)path);
1503                 return 0;
1504         }
1505
1506         if (skip_prefix(var, "fetch.fsck.", &var)) {
1507                 if (is_valid_msg_type(var, value))
1508                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1509                                 fsck_msg_types.len ? ',' : '=', var, value);
1510                 else
1511                         warning("Skipping unknown msg id '%s'", var);
1512                 return 0;
1513         }
1514
1515         return git_default_config(var, value, cb);
1516 }
1517
1518 static void fetch_pack_config(void)
1519 {
1520         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1521         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1522         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1523         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1524         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1525
1526         git_config(fetch_pack_config_cb, NULL);
1527 }
1528
1529 static void fetch_pack_setup(void)
1530 {
1531         static int did_setup;
1532         if (did_setup)
1533                 return;
1534         fetch_pack_config();
1535         if (0 <= transfer_unpack_limit)
1536                 unpack_limit = transfer_unpack_limit;
1537         else if (0 <= fetch_unpack_limit)
1538                 unpack_limit = fetch_unpack_limit;
1539         did_setup = 1;
1540 }
1541
1542 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1543 {
1544         struct string_list names = STRING_LIST_INIT_NODUP;
1545         int src, dst;
1546
1547         for (src = dst = 0; src < nr; src++) {
1548                 struct string_list_item *item;
1549                 item = string_list_insert(&names, ref[src]->name);
1550                 if (item->util)
1551                         continue; /* already have it */
1552                 item->util = ref[src];
1553                 if (src != dst)
1554                         ref[dst] = ref[src];
1555                 dst++;
1556         }
1557         for (src = dst; src < nr; src++)
1558                 ref[src] = NULL;
1559         string_list_clear(&names, 0);
1560         return dst;
1561 }
1562
1563 static void update_shallow(struct fetch_pack_args *args,
1564                            struct ref **sought, int nr_sought,
1565                            struct shallow_info *si)
1566 {
1567         struct oid_array ref = OID_ARRAY_INIT;
1568         int *status;
1569         int i;
1570
1571         if (args->deepen && alternate_shallow_file) {
1572                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1573                         unlink_or_warn(git_path_shallow(the_repository));
1574                         rollback_lock_file(&shallow_lock);
1575                 } else
1576                         commit_lock_file(&shallow_lock);
1577                 alternate_shallow_file = NULL;
1578                 return;
1579         }
1580
1581         if (!si->shallow || !si->shallow->nr)
1582                 return;
1583
1584         if (args->cloning) {
1585                 /*
1586                  * remote is shallow, but this is a clone, there are
1587                  * no objects in repo to worry about. Accept any
1588                  * shallow points that exist in the pack (iow in repo
1589                  * after get_pack() and reprepare_packed_git())
1590                  */
1591                 struct oid_array extra = OID_ARRAY_INIT;
1592                 struct object_id *oid = si->shallow->oid;
1593                 for (i = 0; i < si->shallow->nr; i++)
1594                         if (has_object_file(&oid[i]))
1595                                 oid_array_append(&extra, &oid[i]);
1596                 if (extra.nr) {
1597                         setup_alternate_shallow(&shallow_lock,
1598                                                 &alternate_shallow_file,
1599                                                 &extra);
1600                         commit_lock_file(&shallow_lock);
1601                         alternate_shallow_file = NULL;
1602                 }
1603                 oid_array_clear(&extra);
1604                 return;
1605         }
1606
1607         if (!si->nr_ours && !si->nr_theirs)
1608                 return;
1609
1610         remove_nonexistent_theirs_shallow(si);
1611         if (!si->nr_ours && !si->nr_theirs)
1612                 return;
1613         for (i = 0; i < nr_sought; i++)
1614                 oid_array_append(&ref, &sought[i]->old_oid);
1615         si->ref = &ref;
1616
1617         if (args->update_shallow) {
1618                 /*
1619                  * remote is also shallow, .git/shallow may be updated
1620                  * so all refs can be accepted. Make sure we only add
1621                  * shallow roots that are actually reachable from new
1622                  * refs.
1623                  */
1624                 struct oid_array extra = OID_ARRAY_INIT;
1625                 struct object_id *oid = si->shallow->oid;
1626                 assign_shallow_commits_to_refs(si, NULL, NULL);
1627                 if (!si->nr_ours && !si->nr_theirs) {
1628                         oid_array_clear(&ref);
1629                         return;
1630                 }
1631                 for (i = 0; i < si->nr_ours; i++)
1632                         oid_array_append(&extra, &oid[si->ours[i]]);
1633                 for (i = 0; i < si->nr_theirs; i++)
1634                         oid_array_append(&extra, &oid[si->theirs[i]]);
1635                 setup_alternate_shallow(&shallow_lock,
1636                                         &alternate_shallow_file,
1637                                         &extra);
1638                 commit_lock_file(&shallow_lock);
1639                 oid_array_clear(&extra);
1640                 oid_array_clear(&ref);
1641                 alternate_shallow_file = NULL;
1642                 return;
1643         }
1644
1645         /*
1646          * remote is also shallow, check what ref is safe to update
1647          * without updating .git/shallow
1648          */
1649         status = xcalloc(nr_sought, sizeof(*status));
1650         assign_shallow_commits_to_refs(si, NULL, status);
1651         if (si->nr_ours || si->nr_theirs) {
1652                 for (i = 0; i < nr_sought; i++)
1653                         if (status[i])
1654                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1655         }
1656         free(status);
1657         oid_array_clear(&ref);
1658 }
1659
1660 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1661 {
1662         struct ref **rm = cb_data;
1663         struct ref *ref = *rm;
1664
1665         if (!ref)
1666                 return -1; /* end of the list */
1667         *rm = ref->next;
1668         oidcpy(oid, &ref->old_oid);
1669         return 0;
1670 }
1671
1672 struct ref *fetch_pack(struct fetch_pack_args *args,
1673                        int fd[],
1674                        const struct ref *ref,
1675                        struct ref **sought, int nr_sought,
1676                        struct oid_array *shallow,
1677                        char **pack_lockfile,
1678                        enum protocol_version version)
1679 {
1680         struct ref *ref_cpy;
1681         struct shallow_info si;
1682         struct oid_array shallows_scratch = OID_ARRAY_INIT;
1683
1684         fetch_pack_setup();
1685         if (nr_sought)
1686                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1687
1688         if (args->no_dependents && !args->filter_options.choice) {
1689                 /*
1690                  * The protocol does not support requesting that only the
1691                  * wanted objects be sent, so approximate this by setting a
1692                  * "blob:none" filter if no filter is already set. This works
1693                  * for all object types: note that wanted blobs will still be
1694                  * sent because they are directly specified as a "want".
1695                  *
1696                  * NEEDSWORK: Add an option in the protocol to request that
1697                  * only the wanted objects be sent, and implement it.
1698                  */
1699                 parse_list_objects_filter(&args->filter_options, "blob:none");
1700         }
1701
1702         if (version != protocol_v2 && !ref) {
1703                 packet_flush(fd[1]);
1704                 die(_("no matching remote head"));
1705         }
1706         if (version == protocol_v2) {
1707                 if (shallow->nr)
1708                         BUG("Protocol V2 does not provide shallows at this point in the fetch");
1709                 memset(&si, 0, sizeof(si));
1710                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1711                                            &shallows_scratch, &si,
1712                                            pack_lockfile);
1713         } else {
1714                 prepare_shallow_info(&si, shallow);
1715                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1716                                         &si, pack_lockfile);
1717         }
1718         reprepare_packed_git(the_repository);
1719
1720         if (!args->cloning && args->deepen) {
1721                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1722                 struct ref *iterator = ref_cpy;
1723                 opt.shallow_file = alternate_shallow_file;
1724                 if (args->deepen)
1725                         opt.is_deepening_fetch = 1;
1726                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1727                         error(_("remote did not send all necessary objects"));
1728                         free_refs(ref_cpy);
1729                         ref_cpy = NULL;
1730                         rollback_lock_file(&shallow_lock);
1731                         goto cleanup;
1732                 }
1733                 args->connectivity_checked = 1;
1734         }
1735
1736         update_shallow(args, sought, nr_sought, &si);
1737 cleanup:
1738         clear_shallow_info(&si);
1739         oid_array_clear(&shallows_scratch);
1740         return ref_cpy;
1741 }
1742
1743 int report_unmatched_refs(struct ref **sought, int nr_sought)
1744 {
1745         int i, ret = 0;
1746
1747         for (i = 0; i < nr_sought; i++) {
1748                 if (!sought[i])
1749                         continue;
1750                 switch (sought[i]->match_status) {
1751                 case REF_MATCHED:
1752                         continue;
1753                 case REF_NOT_MATCHED:
1754                         error(_("no such remote ref %s"), sought[i]->name);
1755                         break;
1756                 case REF_UNADVERTISED_NOT_ALLOWED:
1757                         error(_("Server does not allow request for unadvertised object %s"),
1758                               sought[i]->name);
1759                         break;
1760                 }
1761                 ret = 1;
1762         }
1763         return ret;
1764 }