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