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