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