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_fsck_objects = 1;
  14 static int receive_unpack_limit = -1;
  15 static int transfer_unpack_limit = -1;
  16 static int unpack_limit = 100;
  17 static int report_status;
  18
  19 static char capabilities[] = " report-status delete-refs ";
  20 static int capabilities_sent;
  21
  22 static int receive_pack_config(const char *var, const char *value)
  23 {
  24         if (strcmp(var, "receive.denynonfastforwards") == 0) {
  25                 deny_non_fast_forwards = git_config_bool(var, value);
  26                 return 0;
  27         }
  28
  29         if (strcmp(var, "receive.unpacklimit") == 0) {
  30                 receive_unpack_limit = git_config_int(var, value);
  31                 return 0;
  32         }
  33
  34         if (strcmp(var, "transfer.unpacklimit") == 0) {
  35                 transfer_unpack_limit = git_config_int(var, value);
  36                 return 0;
  37         }
  38
  39         if (strcmp(var, "receive.fsckobjects") == 0) {
  40                 receive_fsck_objects = git_config_bool(var, value);
  41                 return 0;
  42         }
  43
  44         return git_default_config(var, value);
  45 }
  46
  47 static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  48 {
  49         if (capabilities_sent)
  50                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  51         else
  52                 packet_write(1, "%s %s%c%s\n",
  53                              sha1_to_hex(sha1), path, 0, capabilities);
  54         capabilities_sent = 1;
  55         return 0;
  56 }
  57
  58 static void write_head_info(void)
  59 {
  60         for_each_ref(show_ref, NULL);
  61         if (!capabilities_sent)
  62                 show_ref("capabilities^{}", null_sha1, 0, NULL);
  63
  64 }
  65
  66 struct command {
  67         struct command *next;
  68         const char *error_string;
  69         unsigned char old_sha1[20];
  70         unsigned char new_sha1[20];
  71         char ref_name[FLEX_ARRAY]; /* more */
  72 };
  73
  74 static struct command *commands;
  75
  76 static const char pre_receive_hook[] = "hooks/pre-receive";
  77 static const char post_receive_hook[] = "hooks/post-receive";
  78
  79 static int hook_status(int code, const char *hook_name)
  80 {
  81         switch (code) {
  82         case 0:
  83                 return 0;
  84         case -ERR_RUN_COMMAND_FORK:
  85                 return error("hook fork failed");
  86         case -ERR_RUN_COMMAND_EXEC:
  87                 return error("hook execute failed");
  88         case -ERR_RUN_COMMAND_PIPE:
  89                 return error("hook pipe failed");
  90         case -ERR_RUN_COMMAND_WAITPID:
  91                 return error("waitpid failed");
  92         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  93                 return error("waitpid is confused");
  94         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  95                 return error("%s died of signal", hook_name);
  96         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  97                 return error("%s died strangely", hook_name);
  98         default:
  99                 error("%s exited with error code %d", hook_name, -code);
 100                 return -code;
 101         }
 102 }
 103
 104 static int run_hook(const char *hook_name)
 105 {
 106         static char buf[sizeof(commands->old_sha1) * 2 + PATH_MAX + 4];
 107         struct command *cmd;
 108         struct child_process proc;
 109         const char *argv[2];
 110         int have_input = 0, code;
 111
 112         for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
 113                 if (!cmd->error_string)
 114                         have_input = 1;
 115         }
 116
 117         if (!have_input || access(hook_name, X_OK) < 0)
 118                 return 0;
 119
 120         argv[0] = hook_name;
 121         argv[1] = NULL;
 122
 123         memset(&proc, 0, sizeof(proc));
 124         proc.argv = argv;
 125         proc.in = -1;
 126         proc.stdout_to_stderr = 1;
 127
 128         code = start_command(&proc);
 129         if (code)
 130                 return hook_status(code, hook_name);
 131         for (cmd = commands; cmd; cmd = cmd->next) {
 132                 if (!cmd->error_string) {
 133                         size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
 134                                 sha1_to_hex(cmd->old_sha1),
 135                                 sha1_to_hex(cmd->new_sha1),
 136                                 cmd->ref_name);
 137                         if (write_in_full(proc.in, buf, n) != n)
 138                                 break;
 139                 }
 140         }
 141         return hook_status(finish_command(&proc), hook_name);
 142 }
 143
 144 static int run_update_hook(struct command *cmd)
 145 {
 146         static const char update_hook[] = "hooks/update";
 147         struct child_process proc;
 148         const char *argv[5];
 149
 150         if (access(update_hook, X_OK) < 0)
 151                 return 0;
 152
 153         argv[0] = update_hook;
 154         argv[1] = cmd->ref_name;
 155         argv[2] = sha1_to_hex(cmd->old_sha1);
 156         argv[3] = sha1_to_hex(cmd->new_sha1);
 157         argv[4] = NULL;
 158
 159         memset(&proc, 0, sizeof(proc));
 160         proc.argv = argv;
 161         proc.no_stdin = 1;
 162         proc.stdout_to_stderr = 1;
 163
 164         return hook_status(run_command(&proc), update_hook);
 165 }
 166
 167 static const char *update(struct command *cmd)
 168 {
 169         const char *name = cmd->ref_name;
 170         unsigned char *old_sha1 = cmd->old_sha1;
 171         unsigned char *new_sha1 = cmd->new_sha1;
 172         struct ref_lock *lock;
 173
 174         /* only refs/... are allowed */
 175         if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
 176                 error("refusing to create funny ref '%s' remotely", name);
 177                 return "funny refname";
 178         }
 179
 180         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 181                 error("unpack should have generated %s, "
 182                       "but I can't find it!", sha1_to_hex(new_sha1));
 183                 return "bad pack";
 184         }
 185         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 186             !is_null_sha1(old_sha1) &&
 187             !prefixcmp(name, "refs/heads/")) {
 188                 struct object *old_object, *new_object;
 189                 struct commit *old_commit, *new_commit;
 190                 struct commit_list *bases, *ent;
 191
 192                 old_object = parse_object(old_sha1);
 193                 new_object = parse_object(new_sha1);
 194
 195                 if (!old_object || !new_object ||
 196                     old_object->type != OBJ_COMMIT ||
 197                     new_object->type != OBJ_COMMIT) {
 198                         error("bad sha1 objects for %s", name);
 199                         return "bad ref";
 200                 }
 201                 old_commit = (struct commit *)old_object;
 202                 new_commit = (struct commit *)new_object;
 203                 bases = get_merge_bases(old_commit, new_commit, 1);
 204                 for (ent = bases; ent; ent = ent->next)
 205                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 206                                 break;
 207                 free_commit_list(bases);
 208                 if (!ent) {
 209                         error("denying non-fast forward %s"
 210                               " (you should pull first)", name);
 211                         return "non-fast forward";
 212                 }
 213         }
 214         if (run_update_hook(cmd)) {
 215                 error("hook declined to update %s", name);
 216                 return "hook declined";
 217         }
 218
 219         if (is_null_sha1(new_sha1)) {
 220                 if (!parse_object(old_sha1)) {
 221                         warning ("Allowing deletion of corrupt ref.");
 222                         old_sha1 = NULL;
 223                 }
 224                 if (delete_ref(name, old_sha1)) {
 225                         error("failed to delete %s", name);
 226                         return "failed to delete";
 227                 }
 228                 return NULL; /* good */
 229         }
 230         else {
 231                 lock = lock_any_ref_for_update(name, old_sha1, 0);
 232                 if (!lock) {
 233                         error("failed to lock %s", name);
 234                         return "failed to lock";
 235                 }
 236                 if (write_ref_sha1(lock, new_sha1, "push")) {
 237                         return "failed to write"; /* error() already called */
 238                 }
 239                 return NULL; /* good */
 240         }
 241 }
 242
 243 static char update_post_hook[] = "hooks/post-update";
 244
 245 static void run_update_post_hook(struct command *cmd)
 246 {
 247         struct command *cmd_p;
 248         int argc;
 249         const char **argv;
 250
 251         for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 252                 if (cmd_p->error_string)
 253                         continue;
 254                 argc++;
 255         }
 256         if (!argc || access(update_post_hook, X_OK) < 0)
 257                 return;
 258         argv = xmalloc(sizeof(*argv) * (2 + argc));
 259         argv[0] = update_post_hook;
 260
 261         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 262                 char *p;
 263                 if (cmd_p->error_string)
 264                         continue;
 265                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 266                 strcpy(p, cmd_p->ref_name);
 267                 argv[argc] = p;
 268                 argc++;
 269         }
 270         argv[argc] = NULL;
 271         run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
 272                 | RUN_COMMAND_STDOUT_TO_STDERR);
 273 }
 274
 275 static void execute_commands(const char *unpacker_error)
 276 {
 277         struct command *cmd = commands;
 278
 279         if (unpacker_error) {
 280                 while (cmd) {
 281                         cmd->error_string = "n/a (unpacker error)";
 282                         cmd = cmd->next;
 283                 }
 284                 return;
 285         }
 286
 287         if (run_hook(pre_receive_hook)) {
 288                 while (cmd) {
 289                         cmd->error_string = "pre-receive hook declined";
 290                         cmd = cmd->next;
 291                 }
 292                 return;
 293         }
 294
 295         while (cmd) {
 296                 cmd->error_string = update(cmd);
 297                 cmd = cmd->next;
 298         }
 299 }
 300
 301 static void read_head_info(void)
 302 {
 303         struct command **p = &commands;
 304         for (;;) {
 305                 static char line[1000];
 306                 unsigned char old_sha1[20], new_sha1[20];
 307                 struct command *cmd;
 308                 char *refname;
 309                 int len, reflen;
 310
 311                 len = packet_read_line(0, line, sizeof(line));
 312                 if (!len)
 313                         break;
 314                 if (line[len-1] == '\n')
 315                         line[--len] = 0;
 316                 if (len < 83 ||
 317                     line[40] != ' ' ||
 318                     line[81] != ' ' ||
 319                     get_sha1_hex(line, old_sha1) ||
 320                     get_sha1_hex(line + 41, new_sha1))
 321                         die("protocol error: expected old/new/ref, got '%s'",
 322                             line);
 323
 324                 refname = line + 82;
 325                 reflen = strlen(refname);
 326                 if (reflen + 82 < len) {
 327                         if (strstr(refname + reflen + 1, "report-status"))
 328                                 report_status = 1;
 329                 }
 330                 cmd = xmalloc(sizeof(struct command) + len - 80);
 331                 hashcpy(cmd->old_sha1, old_sha1);
 332                 hashcpy(cmd->new_sha1, new_sha1);
 333                 memcpy(cmd->ref_name, line + 82, len - 81);
 334                 cmd->error_string = NULL;
 335                 cmd->next = NULL;
 336                 *p = cmd;
 337                 p = &cmd->next;
 338         }
 339 }
 340
 341 static const char *parse_pack_header(struct pack_header *hdr)
 342 {
 343         switch (read_pack_header(0, hdr)) {
 344         case PH_ERROR_EOF:
 345                 return "eof before pack header was fully read";
 346
 347         case PH_ERROR_PACK_SIGNATURE:
 348                 return "protocol error (pack signature mismatch detected)";
 349
 350         case PH_ERROR_PROTOCOL:
 351                 return "protocol error (pack version unsupported)";
 352
 353         default:
 354                 return "unknown error in parse_pack_header";
 355
 356         case 0:
 357                 return NULL;
 358         }
 359 }
 360
 361 static const char *pack_lockfile;
 362
 363 static const char *unpack(void)
 364 {
 365         struct pack_header hdr;
 366         const char *hdr_err;
 367         char hdr_arg[38];
 368
 369         hdr_err = parse_pack_header(&hdr);
 370         if (hdr_err)
 371                 return hdr_err;
 372         snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 373                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 374
 375         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 376                 int code, i = 0;
 377                 const char *unpacker[4];
 378                 unpacker[i++] = "unpack-objects";
 379                 if (receive_fsck_objects)
 380                         unpacker[i++] = "--strict";
 381                 unpacker[i++] = hdr_arg;
 382                 unpacker[i++] = NULL;
 383                 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
 384                 switch (code) {
 385                 case 0:
 386                         return NULL;
 387                 case -ERR_RUN_COMMAND_FORK:
 388                         return "unpack fork failed";
 389                 case -ERR_RUN_COMMAND_EXEC:
 390                         return "unpack execute failed";
 391                 case -ERR_RUN_COMMAND_WAITPID:
 392                         return "waitpid failed";
 393                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 394                         return "waitpid is confused";
 395                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 396                         return "unpacker died of signal";
 397                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 398                         return "unpacker died strangely";
 399                 default:
 400                         return "unpacker exited with error code";
 401                 }
 402         } else {
 403                 const char *keeper[7];
 404                 int s, status, i = 0;
 405                 char keep_arg[256];
 406                 struct child_process ip;
 407
 408                 s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
 409                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 410                         strcpy(keep_arg + s, "localhost");
 411
 412                 keeper[i++] = "index-pack";
 413                 keeper[i++] = "--stdin";
 414                 if (receive_fsck_objects)
 415                         keeper[i++] = "--strict";
 416                 keeper[i++] = "--fix-thin";
 417                 keeper[i++] = hdr_arg;
 418                 keeper[i++] = keep_arg;
 419                 keeper[i++] = NULL;
 420                 memset(&ip, 0, sizeof(ip));
 421                 ip.argv = keeper;
 422                 ip.out = -1;
 423                 ip.git_cmd = 1;
 424                 if (start_command(&ip))
 425                         return "index-pack fork failed";
 426                 pack_lockfile = index_pack_lockfile(ip.out);
 427                 status = finish_command(&ip);
 428                 if (!status) {
 429                         reprepare_packed_git();
 430                         return NULL;
 431                 }
 432                 return "index-pack abnormal exit";
 433         }
 434 }
 435
 436 static void report(const char *unpack_status)
 437 {
 438         struct command *cmd;
 439         packet_write(1, "unpack %s\n",
 440                      unpack_status ? unpack_status : "ok");
 441         for (cmd = commands; cmd; cmd = cmd->next) {
 442                 if (!cmd->error_string)
 443                         packet_write(1, "ok %s\n",
 444                                      cmd->ref_name);
 445                 else
 446                         packet_write(1, "ng %s %s\n",
 447                                      cmd->ref_name, cmd->error_string);
 448         }
 449         packet_flush(1);
 450 }
 451
 452 static int delete_only(struct command *cmd)
 453 {
 454         while (cmd) {
 455                 if (!is_null_sha1(cmd->new_sha1))
 456                         return 0;
 457                 cmd = cmd->next;
 458         }
 459         return 1;
 460 }
 461
 462 int main(int argc, char **argv)
 463 {
 464         int i;
 465         char *dir = NULL;
 466
 467         argv++;
 468         for (i = 1; i < argc; i++) {
 469                 char *arg = *argv++;
 470
 471                 if (*arg == '-') {
 472                         /* Do flag handling here */
 473                         usage(receive_pack_usage);
 474                 }
 475                 if (dir)
 476                         usage(receive_pack_usage);
 477                 dir = arg;
 478         }
 479         if (!dir)
 480                 usage(receive_pack_usage);
 481
 482         if (!enter_repo(dir, 0))
 483                 die("'%s': unable to chdir or not a git archive", dir);
 484
 485         if (is_repository_shallow())
 486                 die("attempt to push into a shallow repository");
 487
 488         git_config(receive_pack_config);
 489
 490         if (0 <= transfer_unpack_limit)
 491                 unpack_limit = transfer_unpack_limit;
 492         else if (0 <= receive_unpack_limit)
 493                 unpack_limit = receive_unpack_limit;
 494
 495         write_head_info();
 496
 497         /* EOF */
 498         packet_flush(1);
 499
 500         read_head_info();
 501         if (commands) {
 502                 const char *unpack_status = NULL;
 503
 504                 if (!delete_only(commands))
 505                         unpack_status = unpack();
 506                 execute_commands(unpack_status);
 507                 if (pack_lockfile)
 508                         unlink(pack_lockfile);
 509                 if (report_status)
 510                         report(unpack_status);
 511                 run_hook(post_receive_hook);
 512                 run_update_post_hook(commands);
 513         }
 514         return 0;
 515 }