Andrew's git / gitweb.git / builtin/receive-pack.c
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builtin / receive-pack.con commit multi-pack-index: provide more helpful usage info (6d68e6a)
   1#include "builtin.h"
   2#include "repository.h"
   3#include "config.h"
   4#include "lockfile.h"
   5#include "pack.h"
   6#include "refs.h"
   7#include "pkt-line.h"
   8#include "sideband.h"
   9#include "run-command.h"
  10#include "exec-cmd.h"
  11#include "commit.h"
  12#include "object.h"
  13#include "remote.h"
  14#include "connect.h"
  15#include "transport.h"
  16#include "string-list.h"
  17#include "sha1-array.h"
  18#include "connected.h"
  19#include "argv-array.h"
  20#include "version.h"
  21#include "tag.h"
  22#include "gpg-interface.h"
  23#include "sigchain.h"
  24#include "fsck.h"
  25#include "tmp-objdir.h"
  26#include "oidset.h"
  27#include "packfile.h"
  28#include "object-store.h"
  29#include "protocol.h"
  30
  31static const char * const receive_pack_usage[] = {
  32        N_("git receive-pack <git-dir>"),
  33        NULL
  34};
  35
  36enum deny_action {
  37        DENY_UNCONFIGURED,
  38        DENY_IGNORE,
  39        DENY_WARN,
  40        DENY_REFUSE,
  41        DENY_UPDATE_INSTEAD
  42};
  43
  44static int deny_deletes;
  45static int deny_non_fast_forwards;
  46static enum deny_action deny_current_branch = DENY_UNCONFIGURED;
  47static enum deny_action deny_delete_current = DENY_UNCONFIGURED;
  48static int receive_fsck_objects = -1;
  49static int transfer_fsck_objects = -1;
  50static struct strbuf fsck_msg_types = STRBUF_INIT;
  51static int receive_unpack_limit = -1;
  52static int transfer_unpack_limit = -1;
  53static int advertise_atomic_push = 1;
  54static int advertise_push_options;
  55static int unpack_limit = 100;
  56static off_t max_input_size;
  57static int report_status;
  58static int use_sideband;
  59static int use_atomic;
  60static int use_push_options;
  61static int quiet;
  62static int prefer_ofs_delta = 1;
  63static int auto_update_server_info;
  64static int auto_gc = 1;
  65static int reject_thin;
  66static int stateless_rpc;
  67static const char *service_dir;
  68static const char *head_name;
  69static void *head_name_to_free;
  70static int sent_capabilities;
  71static int shallow_update;
  72static const char *alt_shallow_file;
  73static struct strbuf push_cert = STRBUF_INIT;
  74static struct object_id push_cert_oid;
  75static struct signature_check sigcheck;
  76static const char *push_cert_nonce;
  77static const char *cert_nonce_seed;
  78
  79static const char *NONCE_UNSOLICITED = "UNSOLICITED";
  80static const char *NONCE_BAD = "BAD";
  81static const char *NONCE_MISSING = "MISSING";
  82static const char *NONCE_OK = "OK";
  83static const char *NONCE_SLOP = "SLOP";
  84static const char *nonce_status;
  85static long nonce_stamp_slop;
  86static timestamp_t nonce_stamp_slop_limit;
  87static struct ref_transaction *transaction;
  88
  89static enum {
  90        KEEPALIVE_NEVER = 0,
  91        KEEPALIVE_AFTER_NUL,
  92        KEEPALIVE_ALWAYS
  93} use_keepalive;
  94static int keepalive_in_sec = 5;
  95
  96static struct tmp_objdir *tmp_objdir;
  97
  98static enum deny_action parse_deny_action(const char *var, const char *value)
  99{
 100        if (value) {
 101                if (!strcasecmp(value, "ignore"))
 102                        return DENY_IGNORE;
 103                if (!strcasecmp(value, "warn"))
 104                        return DENY_WARN;
 105                if (!strcasecmp(value, "refuse"))
 106                        return DENY_REFUSE;
 107                if (!strcasecmp(value, "updateinstead"))
 108                        return DENY_UPDATE_INSTEAD;
 109        }
 110        if (git_config_bool(var, value))
 111                return DENY_REFUSE;
 112        return DENY_IGNORE;
 113}
 114
 115static int receive_pack_config(const char *var, const char *value, void *cb)
 116{
 117        int status = parse_hide_refs_config(var, value, "receive");
 118
 119        if (status)
 120                return status;
 121
 122        if (strcmp(var, "receive.denydeletes") == 0) {
 123                deny_deletes = git_config_bool(var, value);
 124                return 0;
 125        }
 126
 127        if (strcmp(var, "receive.denynonfastforwards") == 0) {
 128                deny_non_fast_forwards = git_config_bool(var, value);
 129                return 0;
 130        }
 131
 132        if (strcmp(var, "receive.unpacklimit") == 0) {
 133                receive_unpack_limit = git_config_int(var, value);
 134                return 0;
 135        }
 136
 137        if (strcmp(var, "transfer.unpacklimit") == 0) {
 138                transfer_unpack_limit = git_config_int(var, value);
 139                return 0;
 140        }
 141
 142        if (strcmp(var, "receive.fsck.skiplist") == 0) {
 143                const char *path;
 144
 145                if (git_config_pathname(&path, var, value))
 146                        return 1;
 147                strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
 148                        fsck_msg_types.len ? ',' : '=', path);
 149                free((char *)path);
 150                return 0;
 151        }
 152
 153        if (skip_prefix(var, "receive.fsck.", &var)) {
 154                if (is_valid_msg_type(var, value))
 155                        strbuf_addf(&fsck_msg_types, "%c%s=%s",
 156                                fsck_msg_types.len ? ',' : '=', var, value);
 157                else
 158                        warning("Skipping unknown msg id '%s'", var);
 159                return 0;
 160        }
 161
 162        if (strcmp(var, "receive.fsckobjects") == 0) {
 163                receive_fsck_objects = git_config_bool(var, value);
 164                return 0;
 165        }
 166
 167        if (strcmp(var, "transfer.fsckobjects") == 0) {
 168                transfer_fsck_objects = git_config_bool(var, value);
 169                return 0;
 170        }
 171
 172        if (!strcmp(var, "receive.denycurrentbranch")) {
 173                deny_current_branch = parse_deny_action(var, value);
 174                return 0;
 175        }
 176
 177        if (strcmp(var, "receive.denydeletecurrent") == 0) {
 178                deny_delete_current = parse_deny_action(var, value);
 179                return 0;
 180        }
 181
 182        if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
 183                prefer_ofs_delta = git_config_bool(var, value);
 184                return 0;
 185        }
 186
 187        if (strcmp(var, "receive.updateserverinfo") == 0) {
 188                auto_update_server_info = git_config_bool(var, value);
 189                return 0;
 190        }
 191
 192        if (strcmp(var, "receive.autogc") == 0) {
 193                auto_gc = git_config_bool(var, value);
 194                return 0;
 195        }
 196
 197        if (strcmp(var, "receive.shallowupdate") == 0) {
 198                shallow_update = git_config_bool(var, value);
 199                return 0;
 200        }
 201
 202        if (strcmp(var, "receive.certnonceseed") == 0)
 203                return git_config_string(&cert_nonce_seed, var, value);
 204
 205        if (strcmp(var, "receive.certnonceslop") == 0) {
 206                nonce_stamp_slop_limit = git_config_ulong(var, value);
 207                return 0;
 208        }
 209
 210        if (strcmp(var, "receive.advertiseatomic") == 0) {
 211                advertise_atomic_push = git_config_bool(var, value);
 212                return 0;
 213        }
 214
 215        if (strcmp(var, "receive.advertisepushoptions") == 0) {
 216                advertise_push_options = git_config_bool(var, value);
 217                return 0;
 218        }
 219
 220        if (strcmp(var, "receive.keepalive") == 0) {
 221                keepalive_in_sec = git_config_int(var, value);
 222                return 0;
 223        }
 224
 225        if (strcmp(var, "receive.maxinputsize") == 0) {
 226                max_input_size = git_config_int64(var, value);
 227                return 0;
 228        }
 229
 230        return git_default_config(var, value, cb);
 231}
 232
 233static void show_ref(const char *path, const struct object_id *oid)
 234{
 235        if (sent_capabilities) {
 236                packet_write_fmt(1, "%s %s\n", oid_to_hex(oid), path);
 237        } else {
 238                struct strbuf cap = STRBUF_INIT;
 239
 240                strbuf_addstr(&cap,
 241                              "report-status delete-refs side-band-64k quiet");
 242                if (advertise_atomic_push)
 243                        strbuf_addstr(&cap, " atomic");
 244                if (prefer_ofs_delta)
 245                        strbuf_addstr(&cap, " ofs-delta");
 246                if (push_cert_nonce)
 247                        strbuf_addf(&cap, " push-cert=%s", push_cert_nonce);
 248                if (advertise_push_options)
 249                        strbuf_addstr(&cap, " push-options");
 250                strbuf_addf(&cap, " agent=%s", git_user_agent_sanitized());
 251                packet_write_fmt(1, "%s %s%c%s\n",
 252                             oid_to_hex(oid), path, 0, cap.buf);
 253                strbuf_release(&cap);
 254                sent_capabilities = 1;
 255        }
 256}
 257
 258static int show_ref_cb(const char *path_full, const struct object_id *oid,
 259                       int flag, void *data)
 260{
 261        struct oidset *seen = data;
 262        const char *path = strip_namespace(path_full);
 263
 264        if (ref_is_hidden(path, path_full))
 265                return 0;
 266
 267        /*
 268         * Advertise refs outside our current namespace as ".have"
 269         * refs, so that the client can use them to minimize data
 270         * transfer but will otherwise ignore them.
 271         */
 272        if (!path) {
 273                if (oidset_insert(seen, oid))
 274                        return 0;
 275                path = ".have";
 276        } else {
 277                oidset_insert(seen, oid);
 278        }
 279        show_ref(path, oid);
 280        return 0;
 281}
 282
 283static void show_one_alternate_ref(const char *refname,
 284                                   const struct object_id *oid,
 285                                   void *data)
 286{
 287        struct oidset *seen = data;
 288
 289        if (oidset_insert(seen, oid))
 290                return;
 291
 292        show_ref(".have", oid);
 293}
 294
 295static void write_head_info(void)
 296{
 297        static struct oidset seen = OIDSET_INIT;
 298
 299        for_each_ref(show_ref_cb, &seen);
 300        for_each_alternate_ref(show_one_alternate_ref, &seen);
 301        oidset_clear(&seen);
 302        if (!sent_capabilities)
 303                show_ref("capabilities^{}", &null_oid);
 304
 305        advertise_shallow_grafts(1);
 306
 307        /* EOF */
 308        packet_flush(1);
 309}
 310
 311struct command {
 312        struct command *next;
 313        const char *error_string;
 314        unsigned int skip_update:1,
 315                     did_not_exist:1;
 316        int index;
 317        struct object_id old_oid;
 318        struct object_id new_oid;
 319        char ref_name[FLEX_ARRAY]; /* more */
 320};
 321
 322static void rp_error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 323static void rp_warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 324
 325static void report_message(const char *prefix, const char *err, va_list params)
 326{
 327        int sz;
 328        char msg[4096];
 329
 330        sz = xsnprintf(msg, sizeof(msg), "%s", prefix);
 331        sz += vsnprintf(msg + sz, sizeof(msg) - sz, err, params);
 332        if (sz > (sizeof(msg) - 1))
 333                sz = sizeof(msg) - 1;
 334        msg[sz++] = '\n';
 335
 336        if (use_sideband)
 337                send_sideband(1, 2, msg, sz, use_sideband);
 338        else
 339                xwrite(2, msg, sz);
 340}
 341
 342static void rp_warning(const char *err, ...)
 343{
 344        va_list params;
 345        va_start(params, err);
 346        report_message("warning: ", err, params);
 347        va_end(params);
 348}
 349
 350static void rp_error(const char *err, ...)
 351{
 352        va_list params;
 353        va_start(params, err);
 354        report_message("error: ", err, params);
 355        va_end(params);
 356}
 357
 358static int copy_to_sideband(int in, int out, void *arg)
 359{
 360        char data[128];
 361        int keepalive_active = 0;
 362
 363        if (keepalive_in_sec <= 0)
 364                use_keepalive = KEEPALIVE_NEVER;
 365        if (use_keepalive == KEEPALIVE_ALWAYS)
 366                keepalive_active = 1;
 367
 368        while (1) {
 369                ssize_t sz;
 370
 371                if (keepalive_active) {
 372                        struct pollfd pfd;
 373                        int ret;
 374
 375                        pfd.fd = in;
 376                        pfd.events = POLLIN;
 377                        ret = poll(&pfd, 1, 1000 * keepalive_in_sec);
 378
 379                        if (ret < 0) {
 380                                if (errno == EINTR)
 381                                        continue;
 382                                else
 383                                        break;
 384                        } else if (ret == 0) {
 385                                /* no data; send a keepalive packet */
 386                                static const char buf[] = "0005\1";
 387                                write_or_die(1, buf, sizeof(buf) - 1);
 388                                continue;
 389                        } /* else there is actual data to read */
 390                }
 391
 392                sz = xread(in, data, sizeof(data));
 393                if (sz <= 0)
 394                        break;
 395
 396                if (use_keepalive == KEEPALIVE_AFTER_NUL && !keepalive_active) {
 397                        const char *p = memchr(data, '\0', sz);
 398                        if (p) {
 399                                /*
 400                                 * The NUL tells us to start sending keepalives. Make
 401                                 * sure we send any other data we read along
 402                                 * with it.
 403                                 */
 404                                keepalive_active = 1;
 405                                send_sideband(1, 2, data, p - data, use_sideband);
 406                                send_sideband(1, 2, p + 1, sz - (p - data + 1), use_sideband);
 407                                continue;
 408                        }
 409                }
 410
 411                /*
 412                 * Either we're not looking for a NUL signal, or we didn't see
 413                 * it yet; just pass along the data.
 414                 */
 415                send_sideband(1, 2, data, sz, use_sideband);
 416        }
 417        close(in);
 418        return 0;
 419}
 420
 421#define HMAC_BLOCK_SIZE 64
 422
 423static void hmac_sha1(unsigned char *out,
 424                      const char *key_in, size_t key_len,
 425                      const char *text, size_t text_len)
 426{
 427        unsigned char key[HMAC_BLOCK_SIZE];
 428        unsigned char k_ipad[HMAC_BLOCK_SIZE];
 429        unsigned char k_opad[HMAC_BLOCK_SIZE];
 430        int i;
 431        git_SHA_CTX ctx;
 432
 433        /* RFC 2104 2. (1) */
 434        memset(key, '\0', HMAC_BLOCK_SIZE);
 435        if (HMAC_BLOCK_SIZE < key_len) {
 436                git_SHA1_Init(&ctx);
 437                git_SHA1_Update(&ctx, key_in, key_len);
 438                git_SHA1_Final(key, &ctx);
 439        } else {
 440                memcpy(key, key_in, key_len);
 441        }
 442
 443        /* RFC 2104 2. (2) & (5) */
 444        for (i = 0; i < sizeof(key); i++) {
 445                k_ipad[i] = key[i] ^ 0x36;
 446                k_opad[i] = key[i] ^ 0x5c;
 447        }
 448
 449        /* RFC 2104 2. (3) & (4) */
 450        git_SHA1_Init(&ctx);
 451        git_SHA1_Update(&ctx, k_ipad, sizeof(k_ipad));
 452        git_SHA1_Update(&ctx, text, text_len);
 453        git_SHA1_Final(out, &ctx);
 454
 455        /* RFC 2104 2. (6) & (7) */
 456        git_SHA1_Init(&ctx);
 457        git_SHA1_Update(&ctx, k_opad, sizeof(k_opad));
 458        git_SHA1_Update(&ctx, out, GIT_SHA1_RAWSZ);
 459        git_SHA1_Final(out, &ctx);
 460}
 461
 462static char *prepare_push_cert_nonce(const char *path, timestamp_t stamp)
 463{
 464        struct strbuf buf = STRBUF_INIT;
 465        unsigned char sha1[GIT_SHA1_RAWSZ];
 466
 467        strbuf_addf(&buf, "%s:%"PRItime, path, stamp);
 468        hmac_sha1(sha1, buf.buf, buf.len, cert_nonce_seed, strlen(cert_nonce_seed));;
 469        strbuf_release(&buf);
 470
 471        /* RFC 2104 5. HMAC-SHA1-80 */
 472        strbuf_addf(&buf, "%"PRItime"-%.*s", stamp, GIT_SHA1_HEXSZ, sha1_to_hex(sha1));
 473        return strbuf_detach(&buf, NULL);
 474}
 475
 476/*
 477 * NEEDSWORK: reuse find_commit_header() from jk/commit-author-parsing
 478 * after dropping "_commit" from its name and possibly moving it out
 479 * of commit.c
 480 */
 481static char *find_header(const char *msg, size_t len, const char *key,
 482                         const char **next_line)
 483{
 484        int key_len = strlen(key);
 485        const char *line = msg;
 486
 487        while (line && line < msg + len) {
 488                const char *eol = strchrnul(line, '\n');
 489
 490                if ((msg + len <= eol) || line == eol)
 491                        return NULL;
 492                if (line + key_len < eol &&
 493                    !memcmp(line, key, key_len) && line[key_len] == ' ') {
 494                        int offset = key_len + 1;
 495                        if (next_line)
 496                                *next_line = *eol ? eol + 1 : eol;
 497                        return xmemdupz(line + offset, (eol - line) - offset);
 498                }
 499                line = *eol ? eol + 1 : NULL;
 500        }
 501        return NULL;
 502}
 503
 504static const char *check_nonce(const char *buf, size_t len)
 505{
 506        char *nonce = find_header(buf, len, "nonce", NULL);
 507        timestamp_t stamp, ostamp;
 508        char *bohmac, *expect = NULL;
 509        const char *retval = NONCE_BAD;
 510
 511        if (!nonce) {
 512                retval = NONCE_MISSING;
 513                goto leave;
 514        } else if (!push_cert_nonce) {
 515                retval = NONCE_UNSOLICITED;
 516                goto leave;
 517        } else if (!strcmp(push_cert_nonce, nonce)) {
 518                retval = NONCE_OK;
 519                goto leave;
 520        }
 521
 522        if (!stateless_rpc) {
 523                /* returned nonce MUST match what we gave out earlier */
 524                retval = NONCE_BAD;
 525                goto leave;
 526        }
 527
 528        /*
 529         * In stateless mode, we may be receiving a nonce issued by
 530         * another instance of the server that serving the same
 531         * repository, and the timestamps may not match, but the
 532         * nonce-seed and dir should match, so we can recompute and
 533         * report the time slop.
 534         *
 535         * In addition, when a nonce issued by another instance has
 536         * timestamp within receive.certnonceslop seconds, we pretend
 537         * as if we issued that nonce when reporting to the hook.
 538         */
 539
 540        /* nonce is concat(<seconds-since-epoch>, "-", <hmac>) */
 541        if (*nonce <= '0' || '9' < *nonce) {
 542                retval = NONCE_BAD;
 543                goto leave;
 544        }
 545        stamp = parse_timestamp(nonce, &bohmac, 10);
 546        if (bohmac == nonce || bohmac[0] != '-') {
 547                retval = NONCE_BAD;
 548                goto leave;
 549        }
 550
 551        expect = prepare_push_cert_nonce(service_dir, stamp);
 552        if (strcmp(expect, nonce)) {
 553                /* Not what we would have signed earlier */
 554                retval = NONCE_BAD;
 555                goto leave;
 556        }
 557
 558        /*
 559         * By how many seconds is this nonce stale?  Negative value
 560         * would mean it was issued by another server with its clock
 561         * skewed in the future.
 562         */
 563        ostamp = parse_timestamp(push_cert_nonce, NULL, 10);
 564        nonce_stamp_slop = (long)ostamp - (long)stamp;
 565
 566        if (nonce_stamp_slop_limit &&
 567            labs(nonce_stamp_slop) <= nonce_stamp_slop_limit) {
 568                /*
 569                 * Pretend as if the received nonce (which passes the
 570                 * HMAC check, so it is not a forged by third-party)
 571                 * is what we issued.
 572                 */
 573                free((void *)push_cert_nonce);
 574                push_cert_nonce = xstrdup(nonce);
 575                retval = NONCE_OK;
 576        } else {
 577                retval = NONCE_SLOP;
 578        }
 579
 580leave:
 581        free(nonce);
 582        free(expect);
 583        return retval;
 584}
 585
 586/*
 587 * Return 1 if there is no push_cert or if the push options in push_cert are
 588 * the same as those in the argument; 0 otherwise.
 589 */
 590static int check_cert_push_options(const struct string_list *push_options)
 591{
 592        const char *buf = push_cert.buf;
 593        int len = push_cert.len;
 594
 595        char *option;
 596        const char *next_line;
 597        int options_seen = 0;
 598
 599        int retval = 1;
 600
 601        if (!len)
 602                return 1;
 603
 604        while ((option = find_header(buf, len, "push-option", &next_line))) {
 605                len -= (next_line - buf);
 606                buf = next_line;
 607                options_seen++;
 608                if (options_seen > push_options->nr
 609                    || strcmp(option,
 610                              push_options->items[options_seen - 1].string)) {
 611                        retval = 0;
 612                        goto leave;
 613                }
 614                free(option);
 615        }
 616
 617        if (options_seen != push_options->nr)
 618                retval = 0;
 619
 620leave:
 621        free(option);
 622        return retval;
 623}
 624
 625static void prepare_push_cert_sha1(struct child_process *proc)
 626{
 627        static int already_done;
 628
 629        if (!push_cert.len)
 630                return;
 631
 632        if (!already_done) {
 633                int bogs /* beginning_of_gpg_sig */;
 634
 635                already_done = 1;
 636                if (write_object_file(push_cert.buf, push_cert.len, "blob",
 637                                      &push_cert_oid))
 638                        oidclr(&push_cert_oid);
 639
 640                memset(&sigcheck, '\0', sizeof(sigcheck));
 641
 642                bogs = parse_signature(push_cert.buf, push_cert.len);
 643                check_signature(push_cert.buf, bogs, push_cert.buf + bogs,
 644                                push_cert.len - bogs, &sigcheck);
 645
 646                nonce_status = check_nonce(push_cert.buf, bogs);
 647        }
 648        if (!is_null_oid(&push_cert_oid)) {
 649                argv_array_pushf(&proc->env_array, "GIT_PUSH_CERT=%s",
 650                                 oid_to_hex(&push_cert_oid));
 651                argv_array_pushf(&proc->env_array, "GIT_PUSH_CERT_SIGNER=%s",
 652                                 sigcheck.signer ? sigcheck.signer : "");
 653                argv_array_pushf(&proc->env_array, "GIT_PUSH_CERT_KEY=%s",
 654                                 sigcheck.key ? sigcheck.key : "");
 655                argv_array_pushf(&proc->env_array, "GIT_PUSH_CERT_STATUS=%c",
 656                                 sigcheck.result);
 657                if (push_cert_nonce) {
 658                        argv_array_pushf(&proc->env_array,
 659                                         "GIT_PUSH_CERT_NONCE=%s",
 660                                         push_cert_nonce);
 661                        argv_array_pushf(&proc->env_array,
 662                                         "GIT_PUSH_CERT_NONCE_STATUS=%s",
 663                                         nonce_status);
 664                        if (nonce_status == NONCE_SLOP)
 665                                argv_array_pushf(&proc->env_array,
 666                                                 "GIT_PUSH_CERT_NONCE_SLOP=%ld",
 667                                                 nonce_stamp_slop);
 668                }
 669        }
 670}
 671
 672struct receive_hook_feed_state {
 673        struct command *cmd;
 674        int skip_broken;
 675        struct strbuf buf;
 676        const struct string_list *push_options;
 677};
 678
 679typedef int (*feed_fn)(void *, const char **, size_t *);
 680static int run_and_feed_hook(const char *hook_name, feed_fn feed,
 681                             struct receive_hook_feed_state *feed_state)
 682{
 683        struct child_process proc = CHILD_PROCESS_INIT;
 684        struct async muxer;
 685        const char *argv[2];
 686        int code;
 687
 688        argv[0] = find_hook(hook_name);
 689        if (!argv[0])
 690                return 0;
 691
 692        argv[1] = NULL;
 693
 694        proc.argv = argv;
 695        proc.in = -1;
 696        proc.stdout_to_stderr = 1;
 697        if (feed_state->push_options) {
 698                int i;
 699                for (i = 0; i < feed_state->push_options->nr; i++)
 700                        argv_array_pushf(&proc.env_array,
 701                                "GIT_PUSH_OPTION_%d=%s", i,
 702                                feed_state->push_options->items[i].string);
 703                argv_array_pushf(&proc.env_array, "GIT_PUSH_OPTION_COUNT=%d",
 704                                 feed_state->push_options->nr);
 705        } else
 706                argv_array_pushf(&proc.env_array, "GIT_PUSH_OPTION_COUNT");
 707
 708        if (tmp_objdir)
 709                argv_array_pushv(&proc.env_array, tmp_objdir_env(tmp_objdir));
 710
 711        if (use_sideband) {
 712                memset(&muxer, 0, sizeof(muxer));
 713                muxer.proc = copy_to_sideband;
 714                muxer.in = -1;
 715                code = start_async(&muxer);
 716                if (code)
 717                        return code;
 718                proc.err = muxer.in;
 719        }
 720
 721        prepare_push_cert_sha1(&proc);
 722
 723        code = start_command(&proc);
 724        if (code) {
 725                if (use_sideband)
 726                        finish_async(&muxer);
 727                return code;
 728        }
 729
 730        sigchain_push(SIGPIPE, SIG_IGN);
 731
 732        while (1) {
 733                const char *buf;
 734                size_t n;
 735                if (feed(feed_state, &buf, &n))
 736                        break;
 737                if (write_in_full(proc.in, buf, n) < 0)
 738                        break;
 739        }
 740        close(proc.in);
 741        if (use_sideband)
 742                finish_async(&muxer);
 743
 744        sigchain_pop(SIGPIPE);
 745
 746        return finish_command(&proc);
 747}
 748
 749static int feed_receive_hook(void *state_, const char **bufp, size_t *sizep)
 750{
 751        struct receive_hook_feed_state *state = state_;
 752        struct command *cmd = state->cmd;
 753
 754        while (cmd &&
 755               state->skip_broken && (cmd->error_string || cmd->did_not_exist))
 756                cmd = cmd->next;
 757        if (!cmd)
 758                return -1; /* EOF */
 759        strbuf_reset(&state->buf);
 760        strbuf_addf(&state->buf, "%s %s %s\n",
 761                    oid_to_hex(&cmd->old_oid), oid_to_hex(&cmd->new_oid),
 762                    cmd->ref_name);
 763        state->cmd = cmd->next;
 764        if (bufp) {
 765                *bufp = state->buf.buf;
 766                *sizep = state->buf.len;
 767        }
 768        return 0;
 769}
 770
 771static int run_receive_hook(struct command *commands,
 772                            const char *hook_name,
 773                            int skip_broken,
 774                            const struct string_list *push_options)
 775{
 776        struct receive_hook_feed_state state;
 777        int status;
 778
 779        strbuf_init(&state.buf, 0);
 780        state.cmd = commands;
 781        state.skip_broken = skip_broken;
 782        if (feed_receive_hook(&state, NULL, NULL))
 783                return 0;
 784        state.cmd = commands;
 785        state.push_options = push_options;
 786        status = run_and_feed_hook(hook_name, feed_receive_hook, &state);
 787        strbuf_release(&state.buf);
 788        return status;
 789}
 790
 791static int run_update_hook(struct command *cmd)
 792{
 793        const char *argv[5];
 794        struct child_process proc = CHILD_PROCESS_INIT;
 795        int code;
 796
 797        argv[0] = find_hook("update");
 798        if (!argv[0])
 799                return 0;
 800
 801        argv[1] = cmd->ref_name;
 802        argv[2] = oid_to_hex(&cmd->old_oid);
 803        argv[3] = oid_to_hex(&cmd->new_oid);
 804        argv[4] = NULL;
 805
 806        proc.no_stdin = 1;
 807        proc.stdout_to_stderr = 1;
 808        proc.err = use_sideband ? -1 : 0;
 809        proc.argv = argv;
 810
 811        code = start_command(&proc);
 812        if (code)
 813                return code;
 814        if (use_sideband)
 815                copy_to_sideband(proc.err, -1, NULL);
 816        return finish_command(&proc);
 817}
 818
 819static int is_ref_checked_out(const char *ref)
 820{
 821        if (is_bare_repository())
 822                return 0;
 823
 824        if (!head_name)
 825                return 0;
 826        return !strcmp(head_name, ref);
 827}
 828
 829static char *refuse_unconfigured_deny_msg =
 830        N_("By default, updating the current branch in a non-bare repository\n"
 831           "is denied, because it will make the index and work tree inconsistent\n"
 832           "with what you pushed, and will require 'git reset --hard' to match\n"
 833           "the work tree to HEAD.\n"
 834           "\n"
 835           "You can set the 'receive.denyCurrentBranch' configuration variable\n"
 836           "to 'ignore' or 'warn' in the remote repository to allow pushing into\n"
 837           "its current branch; however, this is not recommended unless you\n"
 838           "arranged to update its work tree to match what you pushed in some\n"
 839           "other way.\n"
 840           "\n"
 841           "To squelch this message and still keep the default behaviour, set\n"
 842           "'receive.denyCurrentBranch' configuration variable to 'refuse'.");
 843
 844static void refuse_unconfigured_deny(void)
 845{
 846        rp_error("%s", _(refuse_unconfigured_deny_msg));
 847}
 848
 849static char *refuse_unconfigured_deny_delete_current_msg =
 850        N_("By default, deleting the current branch is denied, because the next\n"
 851           "'git clone' won't result in any file checked out, causing confusion.\n"
 852           "\n"
 853           "You can set 'receive.denyDeleteCurrent' configuration variable to\n"
 854           "'warn' or 'ignore' in the remote repository to allow deleting the\n"
 855           "current branch, with or without a warning message.\n"
 856           "\n"
 857           "To squelch this message, you can set it to 'refuse'.");
 858
 859static void refuse_unconfigured_deny_delete_current(void)
 860{
 861        rp_error("%s", _(refuse_unconfigured_deny_delete_current_msg));
 862}
 863
 864static int command_singleton_iterator(void *cb_data, struct object_id *oid);
 865static int update_shallow_ref(struct command *cmd, struct shallow_info *si)
 866{
 867        struct lock_file shallow_lock = LOCK_INIT;
 868        struct oid_array extra = OID_ARRAY_INIT;
 869        struct check_connected_options opt = CHECK_CONNECTED_INIT;
 870        uint32_t mask = 1 << (cmd->index % 32);
 871        int i;
 872
 873        trace_printf_key(&trace_shallow,
 874                         "shallow: update_shallow_ref %s\n", cmd->ref_name);
 875        for (i = 0; i < si->shallow->nr; i++)
 876                if (si->used_shallow[i] &&
 877                    (si->used_shallow[i][cmd->index / 32] & mask) &&
 878                    !delayed_reachability_test(si, i))
 879                        oid_array_append(&extra, &si->shallow->oid[i]);
 880
 881        opt.env = tmp_objdir_env(tmp_objdir);
 882        setup_alternate_shallow(&shallow_lock, &opt.shallow_file, &extra);
 883        if (check_connected(command_singleton_iterator, cmd, &opt)) {
 884                rollback_lock_file(&shallow_lock);
 885                oid_array_clear(&extra);
 886                return -1;
 887        }
 888
 889        commit_lock_file(&shallow_lock);
 890
 891        /*
 892         * Make sure setup_alternate_shallow() for the next ref does
 893         * not lose these new roots..
 894         */
 895        for (i = 0; i < extra.nr; i++)
 896                register_shallow(the_repository, &extra.oid[i]);
 897
 898        si->shallow_ref[cmd->index] = 0;
 899        oid_array_clear(&extra);
 900        return 0;
 901}
 902
 903/*
 904 * NEEDSWORK: we should consolidate various implementions of "are we
 905 * on an unborn branch?" test into one, and make the unified one more
 906 * robust. !get_sha1() based check used here and elsewhere would not
 907 * allow us to tell an unborn branch from corrupt ref, for example.
 908 * For the purpose of fixing "deploy-to-update does not work when
 909 * pushing into an empty repository" issue, this should suffice for
 910 * now.
 911 */
 912static int head_has_history(void)
 913{
 914        struct object_id oid;
 915
 916        return !get_oid("HEAD", &oid);
 917}
 918
 919static const char *push_to_deploy(unsigned char *sha1,
 920                                  struct argv_array *env,
 921                                  const char *work_tree)
 922{
 923        const char *update_refresh[] = {
 924                "update-index", "-q", "--ignore-submodules", "--refresh", NULL
 925        };
 926        const char *diff_files[] = {
 927                "diff-files", "--quiet", "--ignore-submodules", "--", NULL
 928        };
 929        const char *diff_index[] = {
 930                "diff-index", "--quiet", "--cached", "--ignore-submodules",
 931                NULL, "--", NULL
 932        };
 933        const char *read_tree[] = {
 934                "read-tree", "-u", "-m", NULL, NULL
 935        };
 936        struct child_process child = CHILD_PROCESS_INIT;
 937
 938        child.argv = update_refresh;
 939        child.env = env->argv;
 940        child.dir = work_tree;
 941        child.no_stdin = 1;
 942        child.stdout_to_stderr = 1;
 943        child.git_cmd = 1;
 944        if (run_command(&child))
 945                return "Up-to-date check failed";
 946
 947        /* run_command() does not clean up completely; reinitialize */
 948        child_process_init(&child);
 949        child.argv = diff_files;
 950        child.env = env->argv;
 951        child.dir = work_tree;
 952        child.no_stdin = 1;
 953        child.stdout_to_stderr = 1;
 954        child.git_cmd = 1;
 955        if (run_command(&child))
 956                return "Working directory has unstaged changes";
 957
 958        /* diff-index with either HEAD or an empty tree */
 959        diff_index[4] = head_has_history() ? "HEAD" : empty_tree_oid_hex();
 960
 961        child_process_init(&child);
 962        child.argv = diff_index;
 963        child.env = env->argv;
 964        child.no_stdin = 1;
 965        child.no_stdout = 1;
 966        child.stdout_to_stderr = 0;
 967        child.git_cmd = 1;
 968        if (run_command(&child))
 969                return "Working directory has staged changes";
 970
 971        read_tree[3] = sha1_to_hex(sha1);
 972        child_process_init(&child);
 973        child.argv = read_tree;
 974        child.env = env->argv;
 975        child.dir = work_tree;
 976        child.no_stdin = 1;
 977        child.no_stdout = 1;
 978        child.stdout_to_stderr = 0;
 979        child.git_cmd = 1;
 980        if (run_command(&child))
 981                return "Could not update working tree to new HEAD";
 982
 983        return NULL;
 984}
 985
 986static const char *push_to_checkout_hook = "push-to-checkout";
 987
 988static const char *push_to_checkout(unsigned char *sha1,
 989                                    struct argv_array *env,
 990                                    const char *work_tree)
 991{
 992        argv_array_pushf(env, "GIT_WORK_TREE=%s", absolute_path(work_tree));
 993        if (run_hook_le(env->argv, push_to_checkout_hook,
 994                        sha1_to_hex(sha1), NULL))
 995                return "push-to-checkout hook declined";
 996        else
 997                return NULL;
 998}
 999
1000static const char *update_worktree(unsigned char *sha1)
1001{
1002        const char *retval;
1003        const char *work_tree = git_work_tree_cfg ? git_work_tree_cfg : "..";
1004        struct argv_array env = ARGV_ARRAY_INIT;
1005
1006        if (is_bare_repository())
1007                return "denyCurrentBranch = updateInstead needs a worktree";
1008
1009        argv_array_pushf(&env, "GIT_DIR=%s", absolute_path(get_git_dir()));
1010
1011        if (!find_hook(push_to_checkout_hook))
1012                retval = push_to_deploy(sha1, &env, work_tree);
1013        else
1014                retval = push_to_checkout(sha1, &env, work_tree);
1015
1016        argv_array_clear(&env);
1017        return retval;
1018}
1019
1020static const char *update(struct command *cmd, struct shallow_info *si)
1021{
1022        const char *name = cmd->ref_name;
1023        struct strbuf namespaced_name_buf = STRBUF_INIT;
1024        static char *namespaced_name;
1025        const char *ret;
1026        struct object_id *old_oid = &cmd->old_oid;
1027        struct object_id *new_oid = &cmd->new_oid;
1028
1029        /* only refs/... are allowed */
1030        if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
1031                rp_error("refusing to create funny ref '%s' remotely", name);
1032                return "funny refname";
1033        }
1034
1035        strbuf_addf(&namespaced_name_buf, "%s%s", get_git_namespace(), name);
1036        free(namespaced_name);
1037        namespaced_name = strbuf_detach(&namespaced_name_buf, NULL);
1038
1039        if (is_ref_checked_out(namespaced_name)) {
1040                switch (deny_current_branch) {
1041                case DENY_IGNORE:
1042                        break;
1043                case DENY_WARN:
1044                        rp_warning("updating the current branch");
1045                        break;
1046                case DENY_REFUSE:
1047                case DENY_UNCONFIGURED:
1048                        rp_error("refusing to update checked out branch: %s", name);
1049                        if (deny_current_branch == DENY_UNCONFIGURED)
1050                                refuse_unconfigured_deny();
1051                        return "branch is currently checked out";
1052                case DENY_UPDATE_INSTEAD:
1053                        ret = update_worktree(new_oid->hash);
1054                        if (ret)
1055                                return ret;
1056                        break;
1057                }
1058        }
1059
1060        if (!is_null_oid(new_oid) && !has_object_file(new_oid)) {
1061                error("unpack should have generated %s, "
1062                      "but I can't find it!", oid_to_hex(new_oid));
1063                return "bad pack";
1064        }
1065
1066        if (!is_null_oid(old_oid) && is_null_oid(new_oid)) {
1067                if (deny_deletes && starts_with(name, "refs/heads/")) {
1068                        rp_error("denying ref deletion for %s", name);
1069                        return "deletion prohibited";
1070                }
1071
1072                if (head_name && !strcmp(namespaced_name, head_name)) {
1073                        switch (deny_delete_current) {
1074                        case DENY_IGNORE:
1075                                break;
1076                        case DENY_WARN:
1077                                rp_warning("deleting the current branch");
1078                                break;
1079                        case DENY_REFUSE:
1080                        case DENY_UNCONFIGURED:
1081                        case DENY_UPDATE_INSTEAD:
1082                                if (deny_delete_current == DENY_UNCONFIGURED)
1083                                        refuse_unconfigured_deny_delete_current();
1084                                rp_error("refusing to delete the current branch: %s", name);
1085                                return "deletion of the current branch prohibited";
1086                        default:
1087                                return "Invalid denyDeleteCurrent setting";
1088                        }
1089                }
1090        }
1091
1092        if (deny_non_fast_forwards && !is_null_oid(new_oid) &&
1093            !is_null_oid(old_oid) &&
1094            starts_with(name, "refs/heads/")) {
1095                struct object *old_object, *new_object;
1096                struct commit *old_commit, *new_commit;
1097
1098                old_object = parse_object(the_repository, old_oid);
1099                new_object = parse_object(the_repository, new_oid);
1100
1101                if (!old_object || !new_object ||
1102                    old_object->type != OBJ_COMMIT ||
1103                    new_object->type != OBJ_COMMIT) {
1104                        error("bad sha1 objects for %s", name);
1105                        return "bad ref";
1106                }
1107                old_commit = (struct commit *)old_object;
1108                new_commit = (struct commit *)new_object;
1109                if (!in_merge_bases(old_commit, new_commit)) {
1110                        rp_error("denying non-fast-forward %s"
1111                                 " (you should pull first)", name);
1112                        return "non-fast-forward";
1113                }
1114        }
1115        if (run_update_hook(cmd)) {
1116                rp_error("hook declined to update %s", name);
1117                return "hook declined";
1118        }
1119
1120        if (is_null_oid(new_oid)) {
1121                struct strbuf err = STRBUF_INIT;
1122                if (!parse_object(the_repository, old_oid)) {
1123                        old_oid = NULL;
1124                        if (ref_exists(name)) {
1125                                rp_warning("Allowing deletion of corrupt ref.");
1126                        } else {
1127                                rp_warning("Deleting a non-existent ref.");
1128                                cmd->did_not_exist = 1;
1129                        }
1130                }
1131                if (ref_transaction_delete(transaction,
1132                                           namespaced_name,
1133                                           old_oid,
1134                                           0, "push", &err)) {
1135                        rp_error("%s", err.buf);
1136                        strbuf_release(&err);
1137                        return "failed to delete";
1138                }
1139                strbuf_release(&err);
1140                return NULL; /* good */
1141        }
1142        else {
1143                struct strbuf err = STRBUF_INIT;
1144                if (shallow_update && si->shallow_ref[cmd->index] &&
1145                    update_shallow_ref(cmd, si))
1146                        return "shallow error";
1147
1148                if (ref_transaction_update(transaction,
1149                                           namespaced_name,
1150                                           new_oid, old_oid,
1151                                           0, "push",
1152                                           &err)) {
1153                        rp_error("%s", err.buf);
1154                        strbuf_release(&err);
1155
1156                        return "failed to update ref";
1157                }
1158                strbuf_release(&err);
1159
1160                return NULL; /* good */
1161        }
1162}
1163
1164static void run_update_post_hook(struct command *commands)
1165{
1166        struct command *cmd;
1167        struct child_process proc = CHILD_PROCESS_INIT;
1168        const char *hook;
1169
1170        hook = find_hook("post-update");
1171        if (!hook)
1172                return;
1173
1174        for (cmd = commands; cmd; cmd = cmd->next) {
1175                if (cmd->error_string || cmd->did_not_exist)
1176                        continue;
1177                if (!proc.args.argc)
1178                        argv_array_push(&proc.args, hook);
1179                argv_array_push(&proc.args, cmd->ref_name);
1180        }
1181        if (!proc.args.argc)
1182                return;
1183
1184        proc.no_stdin = 1;
1185        proc.stdout_to_stderr = 1;
1186        proc.err = use_sideband ? -1 : 0;
1187
1188        if (!start_command(&proc)) {
1189                if (use_sideband)
1190                        copy_to_sideband(proc.err, -1, NULL);
1191                finish_command(&proc);
1192        }
1193}
1194
1195static void check_aliased_update(struct command *cmd, struct string_list *list)
1196{
1197        struct strbuf buf = STRBUF_INIT;
1198        const char *dst_name;
1199        struct string_list_item *item;
1200        struct command *dst_cmd;
1201        int flag;
1202
1203        strbuf_addf(&buf, "%s%s", get_git_namespace(), cmd->ref_name);
1204        dst_name = resolve_ref_unsafe(buf.buf, 0, NULL, &flag);
1205        strbuf_release(&buf);
1206
1207        if (!(flag & REF_ISSYMREF))
1208                return;
1209
1210        if (!dst_name) {
1211                rp_error("refusing update to broken symref '%s'", cmd->ref_name);
1212                cmd->skip_update = 1;
1213                cmd->error_string = "broken symref";
1214                return;
1215        }
1216        dst_name = strip_namespace(dst_name);
1217
1218        if ((item = string_list_lookup(list, dst_name)) == NULL)
1219                return;
1220
1221        cmd->skip_update = 1;
1222
1223        dst_cmd = (struct command *) item->util;
1224
1225        if (!oidcmp(&cmd->old_oid, &dst_cmd->old_oid) &&
1226            !oidcmp(&cmd->new_oid, &dst_cmd->new_oid))
1227                return;
1228
1229        dst_cmd->skip_update = 1;
1230
1231        rp_error("refusing inconsistent update between symref '%s' (%s..%s) and"
1232                 " its target '%s' (%s..%s)",
1233                 cmd->ref_name,
1234                 find_unique_abbrev(&cmd->old_oid, DEFAULT_ABBREV),
1235                 find_unique_abbrev(&cmd->new_oid, DEFAULT_ABBREV),
1236                 dst_cmd->ref_name,
1237                 find_unique_abbrev(&dst_cmd->old_oid, DEFAULT_ABBREV),
1238                 find_unique_abbrev(&dst_cmd->new_oid, DEFAULT_ABBREV));
1239
1240        cmd->error_string = dst_cmd->error_string =
1241                "inconsistent aliased update";
1242}
1243
1244static void check_aliased_updates(struct command *commands)
1245{
1246        struct command *cmd;
1247        struct string_list ref_list = STRING_LIST_INIT_NODUP;
1248
1249        for (cmd = commands; cmd; cmd = cmd->next) {
1250                struct string_list_item *item =
1251                        string_list_append(&ref_list, cmd->ref_name);
1252                item->util = (void *)cmd;
1253        }
1254        string_list_sort(&ref_list);
1255
1256        for (cmd = commands; cmd; cmd = cmd->next) {
1257                if (!cmd->error_string)
1258                        check_aliased_update(cmd, &ref_list);
1259        }
1260
1261        string_list_clear(&ref_list, 0);
1262}
1263
1264static int command_singleton_iterator(void *cb_data, struct object_id *oid)
1265{
1266        struct command **cmd_list = cb_data;
1267        struct command *cmd = *cmd_list;
1268
1269        if (!cmd || is_null_oid(&cmd->new_oid))
1270                return -1; /* end of list */
1271        *cmd_list = NULL; /* this returns only one */
1272        oidcpy(oid, &cmd->new_oid);
1273        return 0;
1274}
1275
1276static void set_connectivity_errors(struct command *commands,
1277                                    struct shallow_info *si)
1278{
1279        struct command *cmd;
1280
1281        for (cmd = commands; cmd; cmd = cmd->next) {
1282                struct command *singleton = cmd;
1283                struct check_connected_options opt = CHECK_CONNECTED_INIT;
1284
1285                if (shallow_update && si->shallow_ref[cmd->index])
1286                        /* to be checked in update_shallow_ref() */
1287                        continue;
1288
1289                opt.env = tmp_objdir_env(tmp_objdir);
1290                if (!check_connected(command_singleton_iterator, &singleton,
1291                                     &opt))
1292                        continue;
1293
1294                cmd->error_string = "missing necessary objects";
1295        }
1296}
1297
1298struct iterate_data {
1299        struct command *cmds;
1300        struct shallow_info *si;
1301};
1302
1303static int iterate_receive_command_list(void *cb_data, struct object_id *oid)
1304{
1305        struct iterate_data *data = cb_data;
1306        struct command **cmd_list = &data->cmds;
1307        struct command *cmd = *cmd_list;
1308
1309        for (; cmd; cmd = cmd->next) {
1310                if (shallow_update && data->si->shallow_ref[cmd->index])
1311                        /* to be checked in update_shallow_ref() */
1312                        continue;
1313                if (!is_null_oid(&cmd->new_oid) && !cmd->skip_update) {
1314                        oidcpy(oid, &cmd->new_oid);
1315                        *cmd_list = cmd->next;
1316                        return 0;
1317                }
1318        }
1319        *cmd_list = NULL;
1320        return -1; /* end of list */
1321}
1322
1323static void reject_updates_to_hidden(struct command *commands)
1324{
1325        struct strbuf refname_full = STRBUF_INIT;
1326        size_t prefix_len;
1327        struct command *cmd;
1328
1329        strbuf_addstr(&refname_full, get_git_namespace());
1330        prefix_len = refname_full.len;
1331
1332        for (cmd = commands; cmd; cmd = cmd->next) {
1333                if (cmd->error_string)
1334                        continue;
1335
1336                strbuf_setlen(&refname_full, prefix_len);
1337                strbuf_addstr(&refname_full, cmd->ref_name);
1338
1339                if (!ref_is_hidden(cmd->ref_name, refname_full.buf))
1340                        continue;
1341                if (is_null_oid(&cmd->new_oid))
1342                        cmd->error_string = "deny deleting a hidden ref";
1343                else
1344                        cmd->error_string = "deny updating a hidden ref";
1345        }
1346
1347        strbuf_release(&refname_full);
1348}
1349
1350static int should_process_cmd(struct command *cmd)
1351{
1352        return !cmd->error_string && !cmd->skip_update;
1353}
1354
1355static void warn_if_skipped_connectivity_check(struct command *commands,
1356                                               struct shallow_info *si)
1357{
1358        struct command *cmd;
1359        int checked_connectivity = 1;
1360
1361        for (cmd = commands; cmd; cmd = cmd->next) {
1362                if (should_process_cmd(cmd) && si->shallow_ref[cmd->index]) {
1363                        error("BUG: connectivity check has not been run on ref %s",
1364                              cmd->ref_name);
1365                        checked_connectivity = 0;
1366                }
1367        }
1368        if (!checked_connectivity)
1369                BUG("connectivity check skipped???");
1370}
1371
1372static void execute_commands_non_atomic(struct command *commands,
1373                                        struct shallow_info *si)
1374{
1375        struct command *cmd;
1376        struct strbuf err = STRBUF_INIT;
1377
1378        for (cmd = commands; cmd; cmd = cmd->next) {
1379                if (!should_process_cmd(cmd))
1380                        continue;
1381
1382                transaction = ref_transaction_begin(&err);
1383                if (!transaction) {
1384                        rp_error("%s", err.buf);
1385                        strbuf_reset(&err);
1386                        cmd->error_string = "transaction failed to start";
1387                        continue;
1388                }
1389
1390                cmd->error_string = update(cmd, si);
1391
1392                if (!cmd->error_string
1393                    && ref_transaction_commit(transaction, &err)) {
1394                        rp_error("%s", err.buf);
1395                        strbuf_reset(&err);
1396                        cmd->error_string = "failed to update ref";
1397                }
1398                ref_transaction_free(transaction);
1399        }
1400        strbuf_release(&err);
1401}
1402
1403static void execute_commands_atomic(struct command *commands,
1404                                        struct shallow_info *si)
1405{
1406        struct command *cmd;
1407        struct strbuf err = STRBUF_INIT;
1408        const char *reported_error = "atomic push failure";
1409
1410        transaction = ref_transaction_begin(&err);
1411        if (!transaction) {
1412                rp_error("%s", err.buf);
1413                strbuf_reset(&err);
1414                reported_error = "transaction failed to start";
1415                goto failure;
1416        }
1417
1418        for (cmd = commands; cmd; cmd = cmd->next) {
1419                if (!should_process_cmd(cmd))
1420                        continue;
1421
1422                cmd->error_string = update(cmd, si);
1423
1424                if (cmd->error_string)
1425                        goto failure;
1426        }
1427
1428        if (ref_transaction_commit(transaction, &err)) {
1429                rp_error("%s", err.buf);
1430                reported_error = "atomic transaction failed";
1431                goto failure;
1432        }
1433        goto cleanup;
1434
1435failure:
1436        for (cmd = commands; cmd; cmd = cmd->next)
1437                if (!cmd->error_string)
1438                        cmd->error_string = reported_error;
1439
1440cleanup:
1441        ref_transaction_free(transaction);
1442        strbuf_release(&err);
1443}
1444
1445static void execute_commands(struct command *commands,
1446                             const char *unpacker_error,
1447                             struct shallow_info *si,
1448                             const struct string_list *push_options)
1449{
1450        struct check_connected_options opt = CHECK_CONNECTED_INIT;
1451        struct command *cmd;
1452        struct iterate_data data;
1453        struct async muxer;
1454        int err_fd = 0;
1455
1456        if (unpacker_error) {
1457                for (cmd = commands; cmd; cmd = cmd->next)
1458                        cmd->error_string = "unpacker error";
1459                return;
1460        }
1461
1462        if (use_sideband) {
1463                memset(&muxer, 0, sizeof(muxer));
1464                muxer.proc = copy_to_sideband;
1465                muxer.in = -1;
1466                if (!start_async(&muxer))
1467                        err_fd = muxer.in;
1468                /* ...else, continue without relaying sideband */
1469        }
1470
1471        data.cmds = commands;
1472        data.si = si;
1473        opt.err_fd = err_fd;
1474        opt.progress = err_fd && !quiet;
1475        opt.env = tmp_objdir_env(tmp_objdir);
1476        if (check_connected(iterate_receive_command_list, &data, &opt))
1477                set_connectivity_errors(commands, si);
1478
1479        if (use_sideband)
1480                finish_async(&muxer);
1481
1482        reject_updates_to_hidden(commands);
1483
1484        if (run_receive_hook(commands, "pre-receive", 0, push_options)) {
1485                for (cmd = commands; cmd; cmd = cmd->next) {
1486                        if (!cmd->error_string)
1487                                cmd->error_string = "pre-receive hook declined";
1488                }
1489                return;
1490        }
1491
1492        /*
1493         * Now we'll start writing out refs, which means the objects need
1494         * to be in their final positions so that other processes can see them.
1495         */
1496        if (tmp_objdir_migrate(tmp_objdir) < 0) {
1497                for (cmd = commands; cmd; cmd = cmd->next) {
1498                        if (!cmd->error_string)
1499                                cmd->error_string = "unable to migrate objects to permanent storage";
1500                }
1501                return;
1502        }
1503        tmp_objdir = NULL;
1504
1505        check_aliased_updates(commands);
1506
1507        free(head_name_to_free);
1508        head_name = head_name_to_free = resolve_refdup("HEAD", 0, NULL, NULL);
1509
1510        if (use_atomic)
1511                execute_commands_atomic(commands, si);
1512        else
1513                execute_commands_non_atomic(commands, si);
1514
1515        if (shallow_update)
1516                warn_if_skipped_connectivity_check(commands, si);
1517}
1518
1519static struct command **queue_command(struct command **tail,
1520                                      const char *line,
1521                                      int linelen)
1522{
1523        struct object_id old_oid, new_oid;
1524        struct command *cmd;
1525        const char *refname;
1526        int reflen;
1527        const char *p;
1528
1529        if (parse_oid_hex(line, &old_oid, &p) ||
1530            *p++ != ' ' ||
1531            parse_oid_hex(p, &new_oid, &p) ||
1532            *p++ != ' ')
1533                die("protocol error: expected old/new/ref, got '%s'", line);
1534
1535        refname = p;
1536        reflen = linelen - (p - line);
1537        FLEX_ALLOC_MEM(cmd, ref_name, refname, reflen);
1538        oidcpy(&cmd->old_oid, &old_oid);
1539        oidcpy(&cmd->new_oid, &new_oid);
1540        *tail = cmd;
1541        return &cmd->next;
1542}
1543
1544static void queue_commands_from_cert(struct command **tail,
1545                                     struct strbuf *push_cert)
1546{
1547        const char *boc, *eoc;
1548
1549        if (*tail)
1550                die("protocol error: got both push certificate and unsigned commands");
1551
1552        boc = strstr(push_cert->buf, "\n\n");
1553        if (!boc)
1554                die("malformed push certificate %.*s", 100, push_cert->buf);
1555        else
1556                boc += 2;
1557        eoc = push_cert->buf + parse_signature(push_cert->buf, push_cert->len);
1558
1559        while (boc < eoc) {
1560                const char *eol = memchr(boc, '\n', eoc - boc);
1561                tail = queue_command(tail, boc, eol ? eol - boc : eoc - boc);
1562                boc = eol ? eol + 1 : eoc;
1563        }
1564}
1565
1566static struct command *read_head_info(struct oid_array *shallow)
1567{
1568        struct command *commands = NULL;
1569        struct command **p = &commands;
1570        for (;;) {
1571                char *line;
1572                int len, linelen;
1573
1574                line = packet_read_line(0, &len);
1575                if (!line)
1576                        break;
1577
1578                if (len > 8 && starts_with(line, "shallow ")) {
1579                        struct object_id oid;
1580                        if (get_oid_hex(line + 8, &oid))
1581                                die("protocol error: expected shallow sha, got '%s'",
1582                                    line + 8);
1583                        oid_array_append(shallow, &oid);
1584                        continue;
1585                }
1586
1587                linelen = strlen(line);
1588                if (linelen < len) {
1589                        const char *feature_list = line + linelen + 1;
1590                        if (parse_feature_request(feature_list, "report-status"))
1591                                report_status = 1;
1592                        if (parse_feature_request(feature_list, "side-band-64k"))
1593                                use_sideband = LARGE_PACKET_MAX;
1594                        if (parse_feature_request(feature_list, "quiet"))
1595                                quiet = 1;
1596                        if (advertise_atomic_push
1597                            && parse_feature_request(feature_list, "atomic"))
1598                                use_atomic = 1;
1599                        if (advertise_push_options
1600                            && parse_feature_request(feature_list, "push-options"))
1601                                use_push_options = 1;
1602                }
1603
1604                if (!strcmp(line, "push-cert")) {
1605                        int true_flush = 0;
1606                        char certbuf[1024];
1607
1608                        for (;;) {
1609                                len = packet_read(0, NULL, NULL,
1610                                                  certbuf, sizeof(certbuf), 0);
1611                                if (!len) {
1612                                        true_flush = 1;
1613                                        break;
1614                                }
1615                                if (!strcmp(certbuf, "push-cert-end\n"))
1616                                        break; /* end of cert */
1617                                strbuf_addstr(&push_cert, certbuf);
1618                        }
1619
1620                        if (true_flush)
1621                                break;
1622                        continue;
1623                }
1624
1625                p = queue_command(p, line, linelen);
1626        }
1627
1628        if (push_cert.len)
1629                queue_commands_from_cert(p, &push_cert);
1630
1631        return commands;
1632}
1633
1634static void read_push_options(struct string_list *options)
1635{
1636        while (1) {
1637                char *line;
1638                int len;
1639
1640                line = packet_read_line(0, &len);
1641
1642                if (!line)
1643                        break;
1644
1645                string_list_append(options, line);
1646        }
1647}
1648
1649static const char *parse_pack_header(struct pack_header *hdr)
1650{
1651        switch (read_pack_header(0, hdr)) {
1652        case PH_ERROR_EOF:
1653                return "eof before pack header was fully read";
1654
1655        case PH_ERROR_PACK_SIGNATURE:
1656                return "protocol error (pack signature mismatch detected)";
1657
1658        case PH_ERROR_PROTOCOL:
1659                return "protocol error (pack version unsupported)";
1660
1661        default:
1662                return "unknown error in parse_pack_header";
1663
1664        case 0:
1665                return NULL;
1666        }
1667}
1668
1669static const char *pack_lockfile;
1670
1671static void push_header_arg(struct argv_array *args, struct pack_header *hdr)
1672{
1673        argv_array_pushf(args, "--pack_header=%"PRIu32",%"PRIu32,
1674                        ntohl(hdr->hdr_version), ntohl(hdr->hdr_entries));
1675}
1676
1677static const char *unpack(int err_fd, struct shallow_info *si)
1678{
1679        struct pack_header hdr;
1680        const char *hdr_err;
1681        int status;
1682        struct child_process child = CHILD_PROCESS_INIT;
1683        int fsck_objects = (receive_fsck_objects >= 0
1684                            ? receive_fsck_objects
1685                            : transfer_fsck_objects >= 0
1686                            ? transfer_fsck_objects
1687                            : 0);
1688
1689        hdr_err = parse_pack_header(&hdr);
1690        if (hdr_err) {
1691                if (err_fd > 0)
1692                        close(err_fd);
1693                return hdr_err;
1694        }
1695
1696        if (si->nr_ours || si->nr_theirs) {
1697                alt_shallow_file = setup_temporary_shallow(si->shallow);
1698                argv_array_push(&child.args, "--shallow-file");
1699                argv_array_push(&child.args, alt_shallow_file);
1700        }
1701
1702        tmp_objdir = tmp_objdir_create();
1703        if (!tmp_objdir) {
1704                if (err_fd > 0)
1705                        close(err_fd);
1706                return "unable to create temporary object directory";
1707        }
1708        child.env = tmp_objdir_env(tmp_objdir);
1709
1710        /*
1711         * Normally we just pass the tmp_objdir environment to the child
1712         * processes that do the heavy lifting, but we may need to see these
1713         * objects ourselves to set up shallow information.
1714         */
1715        tmp_objdir_add_as_alternate(tmp_objdir);
1716
1717        if (ntohl(hdr.hdr_entries) < unpack_limit) {
1718                argv_array_push(&child.args, "unpack-objects");
1719                push_header_arg(&child.args, &hdr);
1720                if (quiet)
1721                        argv_array_push(&child.args, "-q");
1722                if (fsck_objects)
1723                        argv_array_pushf(&child.args, "--strict%s",
1724                                fsck_msg_types.buf);
1725                if (max_input_size)
1726                        argv_array_pushf(&child.args, "--max-input-size=%"PRIuMAX,
1727                                (uintmax_t)max_input_size);
1728                child.no_stdout = 1;
1729                child.err = err_fd;
1730                child.git_cmd = 1;
1731                status = run_command(&child);
1732                if (status)
1733                        return "unpack-objects abnormal exit";
1734        } else {
1735                char hostname[HOST_NAME_MAX + 1];
1736
1737                argv_array_pushl(&child.args, "index-pack", "--stdin", NULL);
1738                push_header_arg(&child.args, &hdr);
1739
1740                if (xgethostname(hostname, sizeof(hostname)))
1741                        xsnprintf(hostname, sizeof(hostname), "localhost");
1742                argv_array_pushf(&child.args,
1743                                 "--keep=receive-pack %"PRIuMAX" on %s",
1744                                 (uintmax_t)getpid(),
1745                                 hostname);
1746
1747                if (!quiet && err_fd)
1748                        argv_array_push(&child.args, "--show-resolving-progress");
1749                if (use_sideband)
1750                        argv_array_push(&child.args, "--report-end-of-input");
1751                if (fsck_objects)
1752                        argv_array_pushf(&child.args, "--strict%s",
1753                                fsck_msg_types.buf);
1754                if (!reject_thin)
1755                        argv_array_push(&child.args, "--fix-thin");
1756                if (max_input_size)
1757                        argv_array_pushf(&child.args, "--max-input-size=%"PRIuMAX,
1758                                (uintmax_t)max_input_size);
1759                child.out = -1;
1760                child.err = err_fd;
1761                child.git_cmd = 1;
1762                status = start_command(&child);
1763                if (status)
1764                        return "index-pack fork failed";
1765                pack_lockfile = index_pack_lockfile(child.out);
1766                close(child.out);
1767                status = finish_command(&child);
1768                if (status)
1769                        return "index-pack abnormal exit";
1770                reprepare_packed_git(the_repository);
1771        }
1772        return NULL;
1773}
1774
1775static const char *unpack_with_sideband(struct shallow_info *si)
1776{
1777        struct async muxer;
1778        const char *ret;
1779
1780        if (!use_sideband)
1781                return unpack(0, si);
1782
1783        use_keepalive = KEEPALIVE_AFTER_NUL;
1784        memset(&muxer, 0, sizeof(muxer));
1785        muxer.proc = copy_to_sideband;
1786        muxer.in = -1;
1787        if (start_async(&muxer))
1788                return NULL;
1789
1790        ret = unpack(muxer.in, si);
1791
1792        finish_async(&muxer);
1793        return ret;
1794}
1795
1796static void prepare_shallow_update(struct command *commands,
1797                                   struct shallow_info *si)
1798{
1799        int i, j, k, bitmap_size = DIV_ROUND_UP(si->ref->nr, 32);
1800
1801        ALLOC_ARRAY(si->used_shallow, si->shallow->nr);
1802        assign_shallow_commits_to_refs(si, si->used_shallow, NULL);
1803
1804        si->need_reachability_test =
1805                xcalloc(si->shallow->nr, sizeof(*si->need_reachability_test));
1806        si->reachable =
1807                xcalloc(si->shallow->nr, sizeof(*si->reachable));
1808        si->shallow_ref = xcalloc(si->ref->nr, sizeof(*si->shallow_ref));
1809
1810        for (i = 0; i < si->nr_ours; i++)
1811                si->need_reachability_test[si->ours[i]] = 1;
1812
1813        for (i = 0; i < si->shallow->nr; i++) {
1814                if (!si->used_shallow[i])
1815                        continue;
1816                for (j = 0; j < bitmap_size; j++) {
1817                        if (!si->used_shallow[i][j])
1818                                continue;
1819                        si->need_reachability_test[i]++;
1820                        for (k = 0; k < 32; k++)
1821                                if (si->used_shallow[i][j] & (1U << k))
1822                                        si->shallow_ref[j * 32 + k]++;
1823                }
1824
1825                /*
1826                 * true for those associated with some refs and belong
1827                 * in "ours" list aka "step 7 not done yet"
1828                 */
1829                si->need_reachability_test[i] =
1830                        si->need_reachability_test[i] > 1;
1831        }
1832
1833        /*
1834         * keep hooks happy by forcing a temporary shallow file via
1835         * env variable because we can't add --shallow-file to every
1836         * command. check_everything_connected() will be done with
1837         * true .git/shallow though.
1838         */
1839        setenv(GIT_SHALLOW_FILE_ENVIRONMENT, alt_shallow_file, 1);
1840}
1841
1842static void update_shallow_info(struct command *commands,
1843                                struct shallow_info *si,
1844                                struct oid_array *ref)
1845{
1846        struct command *cmd;
1847        int *ref_status;
1848        remove_nonexistent_theirs_shallow(si);
1849        if (!si->nr_ours && !si->nr_theirs) {
1850                shallow_update = 0;
1851                return;
1852        }
1853
1854        for (cmd = commands; cmd; cmd = cmd->next) {
1855                if (is_null_oid(&cmd->new_oid))
1856                        continue;
1857                oid_array_append(ref, &cmd->new_oid);
1858                cmd->index = ref->nr - 1;
1859        }
1860        si->ref = ref;
1861
1862        if (shallow_update) {
1863                prepare_shallow_update(commands, si);
1864                return;
1865        }
1866
1867        ALLOC_ARRAY(ref_status, ref->nr);
1868        assign_shallow_commits_to_refs(si, NULL, ref_status);
1869        for (cmd = commands; cmd; cmd = cmd->next) {
1870                if (is_null_oid(&cmd->new_oid))
1871                        continue;
1872                if (ref_status[cmd->index]) {
1873                        cmd->error_string = "shallow update not allowed";
1874                        cmd->skip_update = 1;
1875                }
1876        }
1877        free(ref_status);
1878}
1879
1880static void report(struct command *commands, const char *unpack_status)
1881{
1882        struct command *cmd;
1883        struct strbuf buf = STRBUF_INIT;
1884
1885        packet_buf_write(&buf, "unpack %s\n",
1886                         unpack_status ? unpack_status : "ok");
1887        for (cmd = commands; cmd; cmd = cmd->next) {
1888                if (!cmd->error_string)
1889                        packet_buf_write(&buf, "ok %s\n",
1890                                         cmd->ref_name);
1891                else
1892                        packet_buf_write(&buf, "ng %s %s\n",
1893                                         cmd->ref_name, cmd->error_string);
1894        }
1895        packet_buf_flush(&buf);
1896
1897        if (use_sideband)
1898                send_sideband(1, 1, buf.buf, buf.len, use_sideband);
1899        else
1900                write_or_die(1, buf.buf, buf.len);
1901        strbuf_release(&buf);
1902}
1903
1904static int delete_only(struct command *commands)
1905{
1906        struct command *cmd;
1907        for (cmd = commands; cmd; cmd = cmd->next) {
1908                if (!is_null_oid(&cmd->new_oid))
1909                        return 0;
1910        }
1911        return 1;
1912}
1913
1914int cmd_receive_pack(int argc, const char **argv, const char *prefix)
1915{
1916        int advertise_refs = 0;
1917        struct command *commands;
1918        struct oid_array shallow = OID_ARRAY_INIT;
1919        struct oid_array ref = OID_ARRAY_INIT;
1920        struct shallow_info si;
1921
1922        struct option options[] = {
1923                OPT__QUIET(&quiet, N_("quiet")),
1924                OPT_HIDDEN_BOOL(0, "stateless-rpc", &stateless_rpc, NULL),
1925                OPT_HIDDEN_BOOL(0, "advertise-refs", &advertise_refs, NULL),
1926                OPT_HIDDEN_BOOL(0, "reject-thin-pack-for-testing", &reject_thin, NULL),
1927                OPT_END()
1928        };
1929
1930        packet_trace_identity("receive-pack");
1931
1932        argc = parse_options(argc, argv, prefix, options, receive_pack_usage, 0);
1933
1934        if (argc > 1)
1935                usage_msg_opt(_("Too many arguments."), receive_pack_usage, options);
1936        if (argc == 0)
1937                usage_msg_opt(_("You must specify a directory."), receive_pack_usage, options);
1938
1939        service_dir = argv[0];
1940
1941        setup_path();
1942
1943        if (!enter_repo(service_dir, 0))
1944                die("'%s' does not appear to be a git repository", service_dir);
1945
1946        git_config(receive_pack_config, NULL);
1947        if (cert_nonce_seed)
1948                push_cert_nonce = prepare_push_cert_nonce(service_dir, time(NULL));
1949
1950        if (0 <= transfer_unpack_limit)
1951                unpack_limit = transfer_unpack_limit;
1952        else if (0 <= receive_unpack_limit)
1953                unpack_limit = receive_unpack_limit;
1954
1955        switch (determine_protocol_version_server()) {
1956        case protocol_v2:
1957                /*
1958                 * push support for protocol v2 has not been implemented yet,
1959                 * so ignore the request to use v2 and fallback to using v0.
1960                 */
1961                break;
1962        case protocol_v1:
1963                /*
1964                 * v1 is just the original protocol with a version string,
1965                 * so just fall through after writing the version string.
1966                 */
1967                if (advertise_refs || !stateless_rpc)
1968                        packet_write_fmt(1, "version 1\n");
1969
1970                /* fallthrough */
1971        case protocol_v0:
1972                break;
1973        case protocol_unknown_version:
1974                BUG("unknown protocol version");
1975        }
1976
1977        if (advertise_refs || !stateless_rpc) {
1978                write_head_info();
1979        }
1980        if (advertise_refs)
1981                return 0;
1982
1983        if ((commands = read_head_info(&shallow)) != NULL) {
1984                const char *unpack_status = NULL;
1985                struct string_list push_options = STRING_LIST_INIT_DUP;
1986
1987                if (use_push_options)
1988                        read_push_options(&push_options);
1989                if (!check_cert_push_options(&push_options)) {
1990                        struct command *cmd;
1991                        for (cmd = commands; cmd; cmd = cmd->next)
1992                                cmd->error_string = "inconsistent push options";
1993                }
1994
1995                prepare_shallow_info(&si, &shallow);
1996                if (!si.nr_ours && !si.nr_theirs)
1997                        shallow_update = 0;
1998                if (!delete_only(commands)) {
1999                        unpack_status = unpack_with_sideband(&si);
2000                        update_shallow_info(commands, &si, &ref);
2001                }
2002                use_keepalive = KEEPALIVE_ALWAYS;
2003                execute_commands(commands, unpack_status, &si,
2004                                 &push_options);
2005                if (pack_lockfile)
2006                        unlink_or_warn(pack_lockfile);
2007                if (report_status)
2008                        report(commands, unpack_status);
2009                run_receive_hook(commands, "post-receive", 1,
2010                                 &push_options);
2011                run_update_post_hook(commands);
2012                string_list_clear(&push_options, 0);
2013                if (auto_gc) {
2014                        const char *argv_gc_auto[] = {
2015                                "gc", "--auto", "--quiet", NULL,
2016                        };
2017                        struct child_process proc = CHILD_PROCESS_INIT;
2018
2019                        proc.no_stdin = 1;
2020                        proc.stdout_to_stderr = 1;
2021                        proc.err = use_sideband ? -1 : 0;
2022                        proc.git_cmd = 1;
2023                        proc.argv = argv_gc_auto;
2024
2025                        close_all_packs(the_repository->objects);
2026                        if (!start_command(&proc)) {
2027                                if (use_sideband)
2028                                        copy_to_sideband(proc.err, -1, NULL);
2029                                finish_command(&proc);
2030                        }
2031                }
2032                if (auto_update_server_info)
2033                        update_server_info(0);
2034                clear_shallow_info(&si);
2035        }
2036        if (use_sideband)
2037                packet_flush(1);
2038        oid_array_clear(&shallow);
2039        oid_array_clear(&ref);
2040        free((void *)push_cert_nonce);
2041        return 0;
2042}