receive-pack.c

   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
  10 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
  11
  12 static int deny_non_fast_forwards = 0;
  13 static int receive_unpack_limit = -1;
  14 static int transfer_unpack_limit = -1;
  15 static int unpack_limit = 100;
  16 static int report_status;
  17
  18 static char capabilities[] = " report-status delete-refs ";
  19 static int capabilities_sent;
  20
  21 static 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
  41 static 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
  52 static 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
  60 struct 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
  68 static struct command *commands;
  69
  70 static const char pre_receive_hook[] = "hooks/pre-receive";
  71 static const char post_receive_hook[] = "hooks/post-receive";
  72
  73 static int hook_status(int code, const char *hook_name)
  74 {
  75         switch (code) {
  76         case 0:
  77                 return 0;
  78         case -ERR_RUN_COMMAND_FORK:
  79                 return error("hook fork failed");
  80         case -ERR_RUN_COMMAND_EXEC:
  81                 return error("hook execute failed");
  82         case -ERR_RUN_COMMAND_WAITPID:
  83                 return error("waitpid failed");
  84         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  85                 return error("waitpid is confused");
  86         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  87                 return error("%s died of signal", hook_name);
  88         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  89                 return error("%s died strangely", hook_name);
  90         default:
  91                 error("%s exited with error code %d", hook_name, -code);
  92                 return -code;
  93         }
  94 }
  95
  96 static int run_hook(const char *hook_name,
  97         struct command *first_cmd,
  98         int single)
  99 {
 100         struct command *cmd;
 101         int argc, code;
 102         const char **argv;
 103
 104         for (argc = 0, cmd = first_cmd; cmd; cmd = cmd->next) {
 105                 if (!cmd->error_string)
 106                         argc += 3;
 107                 if (single)
 108                         break;
 109         }
 110
 111         if (!argc || access(hook_name, X_OK) < 0)
 112                 return 0;
 113
 114         argv = xmalloc(sizeof(*argv) * (2 + argc));
 115         argv[0] = hook_name;
 116         for (argc = 1, cmd = first_cmd; cmd; cmd = cmd->next) {
 117                 if (!cmd->error_string) {
 118                         argv[argc++] = xstrdup(cmd->ref_name);
 119                         argv[argc++] = xstrdup(sha1_to_hex(cmd->old_sha1));
 120                         argv[argc++] = xstrdup(sha1_to_hex(cmd->new_sha1));
 121                 }
 122                 if (single)
 123                         break;
 124         }
 125         argv[argc] = NULL;
 126
 127         code = run_command_v_opt(argv,
 128                 RUN_COMMAND_NO_STDIN | RUN_COMMAND_STDOUT_TO_STDERR);
 129         while (--argc > 0)
 130                 free((char*)argv[argc]);
 131         free(argv);
 132
 133         return hook_status(code, hook_name);
 134 }
 135
 136 static int run_update_hook(struct command *cmd)
 137 {
 138         static const char update_hook[] = "hooks/update";
 139         struct child_process proc;
 140         const char *argv[5];
 141
 142         if (access(update_hook, X_OK) < 0)
 143                 return 0;
 144
 145         argv[0] = update_hook;
 146         argv[1] = cmd->ref_name;
 147         argv[2] = sha1_to_hex(cmd->old_sha1);
 148         argv[3] = sha1_to_hex(cmd->new_sha1);
 149         argv[4] = NULL;
 150
 151         memset(&proc, 0, sizeof(proc));
 152         proc.argv = argv;
 153         proc.no_stdin = 1;
 154         proc.stdout_to_stderr = 1;
 155
 156         return hook_status(run_command(&proc), update_hook);
 157 }
 158
 159 static const char *update(struct command *cmd)
 160 {
 161         const char *name = cmd->ref_name;
 162         unsigned char *old_sha1 = cmd->old_sha1;
 163         unsigned char *new_sha1 = cmd->new_sha1;
 164         struct ref_lock *lock;
 165
 166         if (!prefixcmp(name, "refs/") && check_ref_format(name + 5)) {
 167                 error("refusing to create funny ref '%s' locally", name);
 168                 return "funny refname";
 169         }
 170
 171         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 172                 error("unpack should have generated %s, "
 173                       "but I can't find it!", sha1_to_hex(new_sha1));
 174                 return "bad pack";
 175         }
 176         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 177             !is_null_sha1(old_sha1) &&
 178             !prefixcmp(name, "refs/heads/")) {
 179                 struct commit *old_commit, *new_commit;
 180                 struct commit_list *bases, *ent;
 181
 182                 old_commit = (struct commit *)parse_object(old_sha1);
 183                 new_commit = (struct commit *)parse_object(new_sha1);
 184                 bases = get_merge_bases(old_commit, new_commit, 1);
 185                 for (ent = bases; ent; ent = ent->next)
 186                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 187                                 break;
 188                 free_commit_list(bases);
 189                 if (!ent) {
 190                         error("denying non-fast forward %s"
 191                               " (you should pull first)", name);
 192                         return "non-fast forward";
 193                 }
 194         }
 195         if (run_update_hook(cmd)) {
 196                 error("hook declined to update %s", name);
 197                 return "hook declined";
 198         }
 199
 200         if (is_null_sha1(new_sha1)) {
 201                 if (delete_ref(name, old_sha1)) {
 202                         error("failed to delete %s", name);
 203                         return "failed to delete";
 204                 }
 205                 fprintf(stderr, "%s: %s -> deleted\n", name,
 206                         sha1_to_hex(old_sha1));
 207                 return NULL; /* good */
 208         }
 209         else {
 210                 lock = lock_any_ref_for_update(name, old_sha1);
 211                 if (!lock) {
 212                         error("failed to lock %s", name);
 213                         return "failed to lock";
 214                 }
 215                 if (write_ref_sha1(lock, new_sha1, "push")) {
 216                         return "failed to write"; /* error() already called */
 217                 }
 218                 fprintf(stderr, "%s: %s -> %s\n", name,
 219                         sha1_to_hex(old_sha1), sha1_to_hex(new_sha1));
 220                 return NULL; /* good */
 221         }
 222 }
 223
 224 static char update_post_hook[] = "hooks/post-update";
 225
 226 static void run_update_post_hook(struct command *cmd)
 227 {
 228         struct command *cmd_p;
 229         int argc;
 230         const char **argv;
 231
 232         for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 233                 if (cmd_p->error_string)
 234                         continue;
 235                 argc++;
 236         }
 237         if (!argc || access(update_post_hook, X_OK) < 0)
 238                 return;
 239         argv = xmalloc(sizeof(*argv) * (2 + argc));
 240         argv[0] = update_post_hook;
 241
 242         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 243                 char *p;
 244                 if (cmd_p->error_string)
 245                         continue;
 246                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 247                 strcpy(p, cmd_p->ref_name);
 248                 argv[argc] = p;
 249                 argc++;
 250         }
 251         argv[argc] = NULL;
 252         run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
 253                 | RUN_COMMAND_STDOUT_TO_STDERR);
 254 }
 255
 256 static void execute_commands(const char *unpacker_error)
 257 {
 258         struct command *cmd = commands;
 259
 260         if (unpacker_error) {
 261                 while (cmd) {
 262                         cmd->error_string = "n/a (unpacker error)";
 263                         cmd = cmd->next;
 264                 }
 265                 return;
 266         }
 267
 268         if (run_hook(pre_receive_hook, commands, 0)) {
 269                 while (cmd) {
 270                         cmd->error_string = "pre-receive hook declined";
 271                         cmd = cmd->next;
 272                 }
 273                 return;
 274         }
 275
 276         while (cmd) {
 277                 cmd->error_string = update(cmd);
 278                 cmd = cmd->next;
 279         }
 280 }
 281
 282 static void read_head_info(void)
 283 {
 284         struct command **p = &commands;
 285         for (;;) {
 286                 static char line[1000];
 287                 unsigned char old_sha1[20], new_sha1[20];
 288                 struct command *cmd;
 289                 char *refname;
 290                 int len, reflen;
 291
 292                 len = packet_read_line(0, line, sizeof(line));
 293                 if (!len)
 294                         break;
 295                 if (line[len-1] == '\n')
 296                         line[--len] = 0;
 297                 if (len < 83 ||
 298                     line[40] != ' ' ||
 299                     line[81] != ' ' ||
 300                     get_sha1_hex(line, old_sha1) ||
 301                     get_sha1_hex(line + 41, new_sha1))
 302                         die("protocol error: expected old/new/ref, got '%s'",
 303                             line);
 304
 305                 refname = line + 82;
 306                 reflen = strlen(refname);
 307                 if (reflen + 82 < len) {
 308                         if (strstr(refname + reflen + 1, "report-status"))
 309                                 report_status = 1;
 310                 }
 311                 cmd = xmalloc(sizeof(struct command) + len - 80);
 312                 hashcpy(cmd->old_sha1, old_sha1);
 313                 hashcpy(cmd->new_sha1, new_sha1);
 314                 memcpy(cmd->ref_name, line + 82, len - 81);
 315                 cmd->error_string = NULL;
 316                 cmd->next = NULL;
 317                 *p = cmd;
 318                 p = &cmd->next;
 319         }
 320 }
 321
 322 static const char *parse_pack_header(struct pack_header *hdr)
 323 {
 324         switch (read_pack_header(0, hdr)) {
 325         case PH_ERROR_EOF:
 326                 return "eof before pack header was fully read";
 327
 328         case PH_ERROR_PACK_SIGNATURE:
 329                 return "protocol error (pack signature mismatch detected)";
 330
 331         case PH_ERROR_PROTOCOL:
 332                 return "protocol error (pack version unsupported)";
 333
 334         default:
 335                 return "unknown error in parse_pack_header";
 336
 337         case 0:
 338                 return NULL;
 339         }
 340 }
 341
 342 static const char *pack_lockfile;
 343
 344 static const char *unpack(void)
 345 {
 346         struct pack_header hdr;
 347         const char *hdr_err;
 348         char hdr_arg[38];
 349
 350         hdr_err = parse_pack_header(&hdr);
 351         if (hdr_err)
 352                 return hdr_err;
 353         snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 354                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 355
 356         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 357                 int code;
 358                 const char *unpacker[3];
 359                 unpacker[0] = "unpack-objects";
 360                 unpacker[1] = hdr_arg;
 361                 unpacker[2] = NULL;
 362                 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
 363                 switch (code) {
 364                 case 0:
 365                         return NULL;
 366                 case -ERR_RUN_COMMAND_FORK:
 367                         return "unpack fork failed";
 368                 case -ERR_RUN_COMMAND_EXEC:
 369                         return "unpack execute failed";
 370                 case -ERR_RUN_COMMAND_WAITPID:
 371                         return "waitpid failed";
 372                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 373                         return "waitpid is confused";
 374                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 375                         return "unpacker died of signal";
 376                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 377                         return "unpacker died strangely";
 378                 default:
 379                         return "unpacker exited with error code";
 380                 }
 381         } else {
 382                 const char *keeper[6];
 383                 int fd[2], s, len, status;
 384                 pid_t pid;
 385                 char keep_arg[256];
 386                 char packname[46];
 387
 388                 s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
 389                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 390                         strcpy(keep_arg + s, "localhost");
 391
 392                 keeper[0] = "index-pack";
 393                 keeper[1] = "--stdin";
 394                 keeper[2] = "--fix-thin";
 395                 keeper[3] = hdr_arg;
 396                 keeper[4] = keep_arg;
 397                 keeper[5] = NULL;
 398
 399                 if (pipe(fd) < 0)
 400                         return "index-pack pipe failed";
 401                 pid = fork();
 402                 if (pid < 0)
 403                         return "index-pack fork failed";
 404                 if (!pid) {
 405                         dup2(fd[1], 1);
 406                         close(fd[1]);
 407                         close(fd[0]);
 408                         execv_git_cmd(keeper);
 409                         die("execv of index-pack failed");
 410                 }
 411                 close(fd[1]);
 412
 413                 /*
 414                  * The first thing we expects from index-pack's output
 415                  * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
 416                  * %40s is the newly created pack SHA1 name.  In the "keep"
 417                  * case, we need it to remove the corresponding .keep file
 418                  * later on.  If we don't get that then tough luck with it.
 419                  */
 420                 for (len = 0;
 421                      len < 46 && (s = xread(fd[0], packname+len, 46-len)) > 0;
 422                      len += s);
 423                 close(fd[0]);
 424                 if (len == 46 && packname[45] == '\n' &&
 425                     memcmp(packname, "keep\t", 5) == 0) {
 426                         char path[PATH_MAX];
 427                         packname[45] = 0;
 428                         snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
 429                                  get_object_directory(), packname + 5);
 430                         pack_lockfile = xstrdup(path);
 431                 }
 432
 433                 /* Then wrap our index-pack process. */
 434                 while (waitpid(pid, &status, 0) < 0)
 435                         if (errno != EINTR)
 436                                 return "waitpid failed";
 437                 if (WIFEXITED(status)) {
 438                         int code = WEXITSTATUS(status);
 439                         if (code)
 440                                 return "index-pack exited with error code";
 441                         reprepare_packed_git();
 442                         return NULL;
 443                 }
 444                 return "index-pack abnormal exit";
 445         }
 446 }
 447
 448 static void report(const char *unpack_status)
 449 {
 450         struct command *cmd;
 451         packet_write(1, "unpack %s\n",
 452                      unpack_status ? unpack_status : "ok");
 453         for (cmd = commands; cmd; cmd = cmd->next) {
 454                 if (!cmd->error_string)
 455                         packet_write(1, "ok %s\n",
 456                                      cmd->ref_name);
 457                 else
 458                         packet_write(1, "ng %s %s\n",
 459                                      cmd->ref_name, cmd->error_string);
 460         }
 461         packet_flush(1);
 462 }
 463
 464 static int delete_only(struct command *cmd)
 465 {
 466         while (cmd) {
 467                 if (!is_null_sha1(cmd->new_sha1))
 468                         return 0;
 469                 cmd = cmd->next;
 470         }
 471         return 1;
 472 }
 473
 474 int main(int argc, char **argv)
 475 {
 476         int i;
 477         char *dir = NULL;
 478
 479         argv++;
 480         for (i = 1; i < argc; i++) {
 481                 char *arg = *argv++;
 482
 483                 if (*arg == '-') {
 484                         /* Do flag handling here */
 485                         usage(receive_pack_usage);
 486                 }
 487                 if (dir)
 488                         usage(receive_pack_usage);
 489                 dir = arg;
 490         }
 491         if (!dir)
 492                 usage(receive_pack_usage);
 493
 494         if (!enter_repo(dir, 0))
 495                 die("'%s': unable to chdir or not a git archive", dir);
 496
 497         if (is_repository_shallow())
 498                 die("attempt to push into a shallow repository");
 499
 500         git_config(receive_pack_config);
 501
 502         if (0 <= transfer_unpack_limit)
 503                 unpack_limit = transfer_unpack_limit;
 504         else if (0 <= receive_unpack_limit)
 505                 unpack_limit = receive_unpack_limit;
 506
 507         write_head_info();
 508
 509         /* EOF */
 510         packet_flush(1);
 511
 512         read_head_info();
 513         if (commands) {
 514                 const char *unpack_status = NULL;
 515
 516                 if (!delete_only(commands))
 517                         unpack_status = unpack();
 518                 execute_commands(unpack_status);
 519                 if (pack_lockfile)
 520                         unlink(pack_lockfile);
 521                 if (report_status)
 522                         report(unpack_status);
 523                 run_hook(post_receive_hook, commands, 0);
 524                 run_update_post_hook(commands);
 525         }
 526         return 0;
 527 }