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