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