receive-pack.con commit sha1_file.c: Round the mmap offset to half the window size. (78a28df)
   1#include "cache.h"
   2#include "pack.h"
   3#include "refs.h"
   4#include "pkt-line.h"
   5#include "run-command.h"
   6#include "exec_cmd.h"
   7#include "commit.h"
   8#include "object.h"
   9
  10static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
  11
  12static int deny_non_fast_forwards = 0;
  13static int receive_unpack_limit = -1;
  14static int transfer_unpack_limit = -1;
  15static int unpack_limit = 100;
  16static int report_status;
  17
  18static char capabilities[] = " report-status delete-refs ";
  19static int capabilities_sent;
  20
  21static int receive_pack_config(const char *var, const char *value)
  22{
  23        if (strcmp(var, "receive.denynonfastforwards") == 0) {
  24                deny_non_fast_forwards = git_config_bool(var, value);
  25                return 0;
  26        }
  27
  28        if (strcmp(var, "receive.unpacklimit") == 0) {
  29                receive_unpack_limit = git_config_int(var, value);
  30                return 0;
  31        }
  32
  33        if (strcmp(var, "transfer.unpacklimit") == 0) {
  34                transfer_unpack_limit = git_config_int(var, value);
  35                return 0;
  36        }
  37
  38        return git_default_config(var, value);
  39}
  40
  41static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  42{
  43        if (capabilities_sent)
  44                packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  45        else
  46                packet_write(1, "%s %s%c%s\n",
  47                             sha1_to_hex(sha1), path, 0, capabilities);
  48        capabilities_sent = 1;
  49        return 0;
  50}
  51
  52static void write_head_info(void)
  53{
  54        for_each_ref(show_ref, NULL);
  55        if (!capabilities_sent)
  56                show_ref("capabilities^{}", null_sha1, 0, NULL);
  57
  58}
  59
  60struct command {
  61        struct command *next;
  62        const char *error_string;
  63        unsigned char old_sha1[20];
  64        unsigned char new_sha1[20];
  65        char ref_name[FLEX_ARRAY]; /* more */
  66};
  67
  68static struct command *commands;
  69
  70static char update_hook[] = "hooks/update";
  71
  72static int run_update_hook(const char *refname,
  73                           char *old_hex, char *new_hex)
  74{
  75        int code;
  76
  77        if (access(update_hook, X_OK) < 0)
  78                return 0;
  79        code = run_command_opt(RUN_COMMAND_NO_STDIN
  80                | RUN_COMMAND_STDOUT_TO_STDERR,
  81                update_hook, refname, old_hex, new_hex, NULL);
  82        switch (code) {
  83        case 0:
  84                return 0;
  85        case -ERR_RUN_COMMAND_FORK:
  86                return error("hook fork failed");
  87        case -ERR_RUN_COMMAND_EXEC:
  88                return error("hook execute failed");
  89        case -ERR_RUN_COMMAND_WAITPID:
  90                return error("waitpid failed");
  91        case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  92                return error("waitpid is confused");
  93        case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  94                return error("%s died of signal", update_hook);
  95        case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  96                return error("%s died strangely", update_hook);
  97        default:
  98                error("%s exited with error code %d", update_hook, -code);
  99                return -code;
 100        }
 101}
 102
 103static int update(struct command *cmd)
 104{
 105        const char *name = cmd->ref_name;
 106        unsigned char *old_sha1 = cmd->old_sha1;
 107        unsigned char *new_sha1 = cmd->new_sha1;
 108        char new_hex[41], old_hex[41];
 109        struct ref_lock *lock;
 110
 111        cmd->error_string = NULL;
 112        if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 113                cmd->error_string = "funny refname";
 114                return error("refusing to create funny ref '%s' locally",
 115                             name);
 116        }
 117
 118        strcpy(new_hex, sha1_to_hex(new_sha1));
 119        strcpy(old_hex, sha1_to_hex(old_sha1));
 120
 121        if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 122                cmd->error_string = "bad pack";
 123                return error("unpack should have generated %s, "
 124                             "but I can't find it!", new_hex);
 125        }
 126        if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 127            !is_null_sha1(old_sha1) &&
 128            !strncmp(name, "refs/heads/", 11)) {
 129                struct commit *old_commit, *new_commit;
 130                struct commit_list *bases, *ent;
 131
 132                old_commit = (struct commit *)parse_object(old_sha1);
 133                new_commit = (struct commit *)parse_object(new_sha1);
 134                bases = get_merge_bases(old_commit, new_commit, 1);
 135                for (ent = bases; ent; ent = ent->next)
 136                        if (!hashcmp(old_sha1, ent->item->object.sha1))
 137                                break;
 138                free_commit_list(bases);
 139                if (!ent)
 140                        return error("denying non-fast forward;"
 141                                     " you should pull first");
 142        }
 143        if (run_update_hook(name, old_hex, new_hex)) {
 144                cmd->error_string = "hook declined";
 145                return error("hook declined to update %s", name);
 146        }
 147
 148        if (is_null_sha1(new_sha1)) {
 149                if (delete_ref(name, old_sha1)) {
 150                        cmd->error_string = "failed to delete";
 151                        return error("failed to delete %s", name);
 152                }
 153                fprintf(stderr, "%s: %s -> deleted\n", name, old_hex);
 154        }
 155        else {
 156                lock = lock_any_ref_for_update(name, old_sha1);
 157                if (!lock) {
 158                        cmd->error_string = "failed to lock";
 159                        return error("failed to lock %s", name);
 160                }
 161                write_ref_sha1(lock, new_sha1, "push");
 162                fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 163        }
 164        return 0;
 165}
 166
 167static char update_post_hook[] = "hooks/post-update";
 168
 169static void run_update_post_hook(struct command *cmd)
 170{
 171        struct command *cmd_p;
 172        int argc;
 173        const char **argv;
 174
 175        if (access(update_post_hook, X_OK) < 0)
 176                return;
 177        for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 178                if (cmd_p->error_string)
 179                        continue;
 180                argc++;
 181        }
 182        argv = xmalloc(sizeof(*argv) * (1 + argc));
 183        argv[0] = update_post_hook;
 184
 185        for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 186                char *p;
 187                if (cmd_p->error_string)
 188                        continue;
 189                p = xmalloc(strlen(cmd_p->ref_name) + 1);
 190                strcpy(p, cmd_p->ref_name);
 191                argv[argc] = p;
 192                argc++;
 193        }
 194        argv[argc] = NULL;
 195        run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
 196                | RUN_COMMAND_STDOUT_TO_STDERR);
 197}
 198
 199/*
 200 * This gets called after(if) we've successfully
 201 * unpacked the data payload.
 202 */
 203static void execute_commands(void)
 204{
 205        struct command *cmd = commands;
 206
 207        while (cmd) {
 208                update(cmd);
 209                cmd = cmd->next;
 210        }
 211        run_update_post_hook(commands);
 212}
 213
 214static void read_head_info(void)
 215{
 216        struct command **p = &commands;
 217        for (;;) {
 218                static char line[1000];
 219                unsigned char old_sha1[20], new_sha1[20];
 220                struct command *cmd;
 221                char *refname;
 222                int len, reflen;
 223
 224                len = packet_read_line(0, line, sizeof(line));
 225                if (!len)
 226                        break;
 227                if (line[len-1] == '\n')
 228                        line[--len] = 0;
 229                if (len < 83 ||
 230                    line[40] != ' ' ||
 231                    line[81] != ' ' ||
 232                    get_sha1_hex(line, old_sha1) ||
 233                    get_sha1_hex(line + 41, new_sha1))
 234                        die("protocol error: expected old/new/ref, got '%s'",
 235                            line);
 236
 237                refname = line + 82;
 238                reflen = strlen(refname);
 239                if (reflen + 82 < len) {
 240                        if (strstr(refname + reflen + 1, "report-status"))
 241                                report_status = 1;
 242                }
 243                cmd = xmalloc(sizeof(struct command) + len - 80);
 244                hashcpy(cmd->old_sha1, old_sha1);
 245                hashcpy(cmd->new_sha1, new_sha1);
 246                memcpy(cmd->ref_name, line + 82, len - 81);
 247                cmd->error_string = "n/a (unpacker error)";
 248                cmd->next = NULL;
 249                *p = cmd;
 250                p = &cmd->next;
 251        }
 252}
 253
 254static const char *parse_pack_header(struct pack_header *hdr)
 255{
 256        switch (read_pack_header(0, hdr)) {
 257        case PH_ERROR_EOF:
 258                return "eof before pack header was fully read";
 259
 260        case PH_ERROR_PACK_SIGNATURE:
 261                return "protocol error (pack signature mismatch detected)";
 262
 263        case PH_ERROR_PROTOCOL:
 264                return "protocol error (pack version unsupported)";
 265
 266        default:
 267                return "unknown error in parse_pack_header";
 268
 269        case 0:
 270                return NULL;
 271        }
 272}
 273
 274static const char *pack_lockfile;
 275
 276static const char *unpack(void)
 277{
 278        struct pack_header hdr;
 279        const char *hdr_err;
 280        char hdr_arg[38];
 281
 282        hdr_err = parse_pack_header(&hdr);
 283        if (hdr_err)
 284                return hdr_err;
 285        snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 286                        ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 287
 288        if (ntohl(hdr.hdr_entries) < unpack_limit) {
 289                int code;
 290                const char *unpacker[3];
 291                unpacker[0] = "unpack-objects";
 292                unpacker[1] = hdr_arg;
 293                unpacker[2] = NULL;
 294                code = run_command_v_opt(unpacker, RUN_GIT_CMD);
 295                switch (code) {
 296                case 0:
 297                        return NULL;
 298                case -ERR_RUN_COMMAND_FORK:
 299                        return "unpack fork failed";
 300                case -ERR_RUN_COMMAND_EXEC:
 301                        return "unpack execute failed";
 302                case -ERR_RUN_COMMAND_WAITPID:
 303                        return "waitpid failed";
 304                case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 305                        return "waitpid is confused";
 306                case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 307                        return "unpacker died of signal";
 308                case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 309                        return "unpacker died strangely";
 310                default:
 311                        return "unpacker exited with error code";
 312                }
 313        } else {
 314                const char *keeper[6];
 315                int fd[2], s, len, status;
 316                pid_t pid;
 317                char keep_arg[256];
 318                char packname[46];
 319
 320                s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
 321                if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 322                        strcpy(keep_arg + s, "localhost");
 323
 324                keeper[0] = "index-pack";
 325                keeper[1] = "--stdin";
 326                keeper[2] = "--fix-thin";
 327                keeper[3] = hdr_arg;
 328                keeper[4] = keep_arg;
 329                keeper[5] = NULL;
 330
 331                if (pipe(fd) < 0)
 332                        return "index-pack pipe failed";
 333                pid = fork();
 334                if (pid < 0)
 335                        return "index-pack fork failed";
 336                if (!pid) {
 337                        dup2(fd[1], 1);
 338                        close(fd[1]);
 339                        close(fd[0]);
 340                        execv_git_cmd(keeper);
 341                        die("execv of index-pack failed");
 342                }
 343                close(fd[1]);
 344
 345                /*
 346                 * The first thing we expects from index-pack's output
 347                 * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
 348                 * %40s is the newly created pack SHA1 name.  In the "keep"
 349                 * case, we need it to remove the corresponding .keep file
 350                 * later on.  If we don't get that then tough luck with it.
 351                 */
 352                for (len = 0;
 353                     len < 46 && (s = xread(fd[0], packname+len, 46-len)) > 0;
 354                     len += s);
 355                close(fd[0]);
 356                if (len == 46 && packname[45] == '\n' &&
 357                    memcmp(packname, "keep\t", 5) == 0) {
 358                        char path[PATH_MAX];
 359                        packname[45] = 0;
 360                        snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
 361                                 get_object_directory(), packname + 5);
 362                        pack_lockfile = xstrdup(path);
 363                }
 364
 365                /* Then wrap our index-pack process. */
 366                while (waitpid(pid, &status, 0) < 0)
 367                        if (errno != EINTR)
 368                                return "waitpid failed";
 369                if (WIFEXITED(status)) {
 370                        int code = WEXITSTATUS(status);
 371                        if (code)
 372                                return "index-pack exited with error code";
 373                        reprepare_packed_git();
 374                        return NULL;
 375                }
 376                return "index-pack abnormal exit";
 377        }
 378}
 379
 380static void report(const char *unpack_status)
 381{
 382        struct command *cmd;
 383        packet_write(1, "unpack %s\n",
 384                     unpack_status ? unpack_status : "ok");
 385        for (cmd = commands; cmd; cmd = cmd->next) {
 386                if (!cmd->error_string)
 387                        packet_write(1, "ok %s\n",
 388                                     cmd->ref_name);
 389                else
 390                        packet_write(1, "ng %s %s\n",
 391                                     cmd->ref_name, cmd->error_string);
 392        }
 393        packet_flush(1);
 394}
 395
 396static int delete_only(struct command *cmd)
 397{
 398        while (cmd) {
 399                if (!is_null_sha1(cmd->new_sha1))
 400                        return 0;
 401                cmd = cmd->next;
 402        }
 403        return 1;
 404}
 405
 406int main(int argc, char **argv)
 407{
 408        int i;
 409        char *dir = NULL;
 410
 411        argv++;
 412        for (i = 1; i < argc; i++) {
 413                char *arg = *argv++;
 414
 415                if (*arg == '-') {
 416                        /* Do flag handling here */
 417                        usage(receive_pack_usage);
 418                }
 419                if (dir)
 420                        usage(receive_pack_usage);
 421                dir = arg;
 422        }
 423        if (!dir)
 424                usage(receive_pack_usage);
 425
 426        if (!enter_repo(dir, 0))
 427                die("'%s': unable to chdir or not a git archive", dir);
 428
 429        if (is_repository_shallow())
 430                die("attempt to push into a shallow repository");
 431
 432        git_config(receive_pack_config);
 433
 434        if (0 <= transfer_unpack_limit)
 435                unpack_limit = transfer_unpack_limit;
 436        else if (0 <= receive_unpack_limit)
 437                unpack_limit = receive_unpack_limit;
 438
 439        write_head_info();
 440
 441        /* EOF */
 442        packet_flush(1);
 443
 444        read_head_info();
 445        if (commands) {
 446                const char *unpack_status = NULL;
 447
 448                if (!delete_only(commands))
 449                        unpack_status = unpack();
 450                if (!unpack_status)
 451                        execute_commands();
 452                if (pack_lockfile)
 453                        unlink(pack_lockfile);
 454                if (report_status)
 455                        report(unpack_status);
 456        }
 457        return 0;
 458}