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