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