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 char update_hook[] = "hooks/update";
  71
  72 static int run_update_hook(const char *refname,
  73                            char *old_hex, char *new_hex)
  74 {
  75         int code;
  76
  77         if (access(update_hook, X_OK) < 0)
  78                 return 0;
  79         code = run_command_opt(RUN_COMMAND_NO_STDIN
  80                 | RUN_COMMAND_STDOUT_TO_STDERR,
  81                 update_hook, refname, old_hex, new_hex, NULL);
  82         switch (code) {
  83         case 0:
  84                 return 0;
  85         case -ERR_RUN_COMMAND_FORK:
  86                 return error("hook fork failed");
  87         case -ERR_RUN_COMMAND_EXEC:
  88                 return error("hook execute failed");
  89         case -ERR_RUN_COMMAND_WAITPID:
  90                 return error("waitpid failed");
  91         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  92                 return error("waitpid is confused");
  93         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  94                 return error("%s died of signal", update_hook);
  95         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  96                 return error("%s died strangely", update_hook);
  97         default:
  98                 error("%s exited with error code %d", update_hook, -code);
  99                 return -code;
 100         }
 101 }
 102
 103 static int update(struct command *cmd)
 104 {
 105         const char *name = cmd->ref_name;
 106         unsigned char *old_sha1 = cmd->old_sha1;
 107         unsigned char *new_sha1 = cmd->new_sha1;
 108         char new_hex[41], old_hex[41];
 109         struct ref_lock *lock;
 110
 111         cmd->error_string = NULL;
 112         if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 113                 cmd->error_string = "funny refname";
 114                 return error("refusing to create funny ref '%s' locally",
 115                              name);
 116         }
 117
 118         strcpy(new_hex, sha1_to_hex(new_sha1));
 119         strcpy(old_hex, sha1_to_hex(old_sha1));
 120
 121         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 122                 cmd->error_string = "bad pack";
 123                 return error("unpack should have generated %s, "
 124                              "but I can't find it!", new_hex);
 125         }
 126         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 127             !is_null_sha1(old_sha1) &&
 128             !strncmp(name, "refs/heads/", 11)) {
 129                 struct commit *old_commit, *new_commit;
 130                 struct commit_list *bases, *ent;
 131
 132                 old_commit = (struct commit *)parse_object(old_sha1);
 133                 new_commit = (struct commit *)parse_object(new_sha1);
 134                 bases = get_merge_bases(old_commit, new_commit, 1);
 135                 for (ent = bases; ent; ent = ent->next)
 136                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 137                                 break;
 138                 free_commit_list(bases);
 139                 if (!ent)
 140                         return error("denying non-fast forward;"
 141                                      " you should pull first");
 142         }
 143         if (run_update_hook(name, old_hex, new_hex)) {
 144                 cmd->error_string = "hook declined";
 145                 return error("hook declined to update %s", name);
 146         }
 147
 148         if (is_null_sha1(new_sha1)) {
 149                 if (delete_ref(name, old_sha1)) {
 150                         cmd->error_string = "failed to delete";
 151                         return error("failed to delete %s", name);
 152                 }
 153                 fprintf(stderr, "%s: %s -> deleted\n", name, old_hex);
 154         }
 155         else {
 156                 lock = lock_any_ref_for_update(name, old_sha1);
 157                 if (!lock) {
 158                         cmd->error_string = "failed to lock";
 159                         return error("failed to lock %s", name);
 160                 }
 161                 if (write_ref_sha1(lock, new_sha1, "push")) {
 162                         cmd->error_string = "failed to write";
 163                         return -1; /* error() already called */
 164                 }
 165                 fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 166         }
 167         return 0;
 168 }
 169
 170 static char update_post_hook[] = "hooks/post-update";
 171
 172 static void run_update_post_hook(struct command *cmd)
 173 {
 174         struct command *cmd_p;
 175         int argc;
 176         const char **argv;
 177
 178         if (access(update_post_hook, X_OK) < 0)
 179                 return;
 180         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 181                 if (cmd_p->error_string)
 182                         continue;
 183                 argc++;
 184         }
 185         argv = xmalloc(sizeof(*argv) * (1 + argc));
 186         argv[0] = update_post_hook;
 187
 188         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 189                 char *p;
 190                 if (cmd_p->error_string)
 191                         continue;
 192                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 193                 strcpy(p, cmd_p->ref_name);
 194                 argv[argc] = p;
 195                 argc++;
 196         }
 197         argv[argc] = NULL;
 198         run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
 199                 | RUN_COMMAND_STDOUT_TO_STDERR);
 200 }
 201
 202 /*
 203  * This gets called after(if) we've successfully
 204  * unpacked the data payload.
 205  */
 206 static void execute_commands(void)
 207 {
 208         struct command *cmd = commands;
 209
 210         while (cmd) {
 211                 update(cmd);
 212                 cmd = cmd->next;
 213         }
 214         run_update_post_hook(commands);
 215 }
 216
 217 static void read_head_info(void)
 218 {
 219         struct command **p = &commands;
 220         for (;;) {
 221                 static char line[1000];
 222                 unsigned char old_sha1[20], new_sha1[20];
 223                 struct command *cmd;
 224                 char *refname;
 225                 int len, reflen;
 226
 227                 len = packet_read_line(0, line, sizeof(line));
 228                 if (!len)
 229                         break;
 230                 if (line[len-1] == '\n')
 231                         line[--len] = 0;
 232                 if (len < 83 ||
 233                     line[40] != ' ' ||
 234                     line[81] != ' ' ||
 235                     get_sha1_hex(line, old_sha1) ||
 236                     get_sha1_hex(line + 41, new_sha1))
 237                         die("protocol error: expected old/new/ref, got '%s'",
 238                             line);
 239
 240                 refname = line + 82;
 241                 reflen = strlen(refname);
 242                 if (reflen + 82 < len) {
 243                         if (strstr(refname + reflen + 1, "report-status"))
 244                                 report_status = 1;
 245                 }
 246                 cmd = xmalloc(sizeof(struct command) + len - 80);
 247                 hashcpy(cmd->old_sha1, old_sha1);
 248                 hashcpy(cmd->new_sha1, new_sha1);
 249                 memcpy(cmd->ref_name, line + 82, len - 81);
 250                 cmd->error_string = "n/a (unpacker error)";
 251                 cmd->next = NULL;
 252                 *p = cmd;
 253                 p = &cmd->next;
 254         }
 255 }
 256
 257 static const char *parse_pack_header(struct pack_header *hdr)
 258 {
 259         switch (read_pack_header(0, hdr)) {
 260         case PH_ERROR_EOF:
 261                 return "eof before pack header was fully read";
 262
 263         case PH_ERROR_PACK_SIGNATURE:
 264                 return "protocol error (pack signature mismatch detected)";
 265
 266         case PH_ERROR_PROTOCOL:
 267                 return "protocol error (pack version unsupported)";
 268
 269         default:
 270                 return "unknown error in parse_pack_header";
 271
 272         case 0:
 273                 return NULL;
 274         }
 275 }
 276
 277 static const char *pack_lockfile;
 278
 279 static const char *unpack(void)
 280 {
 281         struct pack_header hdr;
 282         const char *hdr_err;
 283         char hdr_arg[38];
 284
 285         hdr_err = parse_pack_header(&hdr);
 286         if (hdr_err)
 287                 return hdr_err;
 288         snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 289                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 290
 291         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 292                 int code;
 293                 const char *unpacker[3];
 294                 unpacker[0] = "unpack-objects";
 295                 unpacker[1] = hdr_arg;
 296                 unpacker[2] = NULL;
 297                 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
 298                 switch (code) {
 299                 case 0:
 300                         return NULL;
 301                 case -ERR_RUN_COMMAND_FORK:
 302                         return "unpack fork failed";
 303                 case -ERR_RUN_COMMAND_EXEC:
 304                         return "unpack execute failed";
 305                 case -ERR_RUN_COMMAND_WAITPID:
 306                         return "waitpid failed";
 307                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 308                         return "waitpid is confused";
 309                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 310                         return "unpacker died of signal";
 311                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 312                         return "unpacker died strangely";
 313                 default:
 314                         return "unpacker exited with error code";
 315                 }
 316         } else {
 317                 const char *keeper[6];
 318                 int fd[2], s, len, status;
 319                 pid_t pid;
 320                 char keep_arg[256];
 321                 char packname[46];
 322
 323                 s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
 324                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 325                         strcpy(keep_arg + s, "localhost");
 326
 327                 keeper[0] = "index-pack";
 328                 keeper[1] = "--stdin";
 329                 keeper[2] = "--fix-thin";
 330                 keeper[3] = hdr_arg;
 331                 keeper[4] = keep_arg;
 332                 keeper[5] = NULL;
 333
 334                 if (pipe(fd) < 0)
 335                         return "index-pack pipe failed";
 336                 pid = fork();
 337                 if (pid < 0)
 338                         return "index-pack fork failed";
 339                 if (!pid) {
 340                         dup2(fd[1], 1);
 341                         close(fd[1]);
 342                         close(fd[0]);
 343                         execv_git_cmd(keeper);
 344                         die("execv of index-pack failed");
 345                 }
 346                 close(fd[1]);
 347
 348                 /*
 349                  * The first thing we expects from index-pack's output
 350                  * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
 351                  * %40s is the newly created pack SHA1 name.  In the "keep"
 352                  * case, we need it to remove the corresponding .keep file
 353                  * later on.  If we don't get that then tough luck with it.
 354                  */
 355                 for (len = 0;
 356                      len < 46 && (s = xread(fd[0], packname+len, 46-len)) > 0;
 357                      len += s);
 358                 close(fd[0]);
 359                 if (len == 46 && packname[45] == '\n' &&
 360                     memcmp(packname, "keep\t", 5) == 0) {
 361                         char path[PATH_MAX];
 362                         packname[45] = 0;
 363                         snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
 364                                  get_object_directory(), packname + 5);
 365                         pack_lockfile = xstrdup(path);
 366                 }
 367
 368                 /* Then wrap our index-pack process. */
 369                 while (waitpid(pid, &status, 0) < 0)
 370                         if (errno != EINTR)
 371                                 return "waitpid failed";
 372                 if (WIFEXITED(status)) {
 373                         int code = WEXITSTATUS(status);
 374                         if (code)
 375                                 return "index-pack exited with error code";
 376                         reprepare_packed_git();
 377                         return NULL;
 378                 }
 379                 return "index-pack abnormal exit";
 380         }
 381 }
 382
 383 static void report(const char *unpack_status)
 384 {
 385         struct command *cmd;
 386         packet_write(1, "unpack %s\n",
 387                      unpack_status ? unpack_status : "ok");
 388         for (cmd = commands; cmd; cmd = cmd->next) {
 389                 if (!cmd->error_string)
 390                         packet_write(1, "ok %s\n",
 391                                      cmd->ref_name);
 392                 else
 393                         packet_write(1, "ng %s %s\n",
 394                                      cmd->ref_name, cmd->error_string);
 395         }
 396         packet_flush(1);
 397 }
 398
 399 static int delete_only(struct command *cmd)
 400 {
 401         while (cmd) {
 402                 if (!is_null_sha1(cmd->new_sha1))
 403                         return 0;
 404                 cmd = cmd->next;
 405         }
 406         return 1;
 407 }
 408
 409 int main(int argc, char **argv)
 410 {
 411         int i;
 412         char *dir = NULL;
 413
 414         argv++;
 415         for (i = 1; i < argc; i++) {
 416                 char *arg = *argv++;
 417
 418                 if (*arg == '-') {
 419                         /* Do flag handling here */
 420                         usage(receive_pack_usage);
 421                 }
 422                 if (dir)
 423                         usage(receive_pack_usage);
 424                 dir = arg;
 425         }
 426         if (!dir)
 427                 usage(receive_pack_usage);
 428
 429         if (!enter_repo(dir, 0))
 430                 die("'%s': unable to chdir or not a git archive", dir);
 431
 432         if (is_repository_shallow())
 433                 die("attempt to push into a shallow repository");
 434
 435         git_config(receive_pack_config);
 436
 437         if (0 <= transfer_unpack_limit)
 438                 unpack_limit = transfer_unpack_limit;
 439         else if (0 <= receive_unpack_limit)
 440                 unpack_limit = receive_unpack_limit;
 441
 442         write_head_info();
 443
 444         /* EOF */
 445         packet_flush(1);
 446
 447         read_head_info();
 448         if (commands) {
 449                 const char *unpack_status = NULL;
 450
 451                 if (!delete_only(commands))
 452                         unpack_status = unpack();
 453                 if (!unpack_status)
 454                         execute_commands();
 455                 if (pack_lockfile)
 456                         unlink(pack_lockfile);
 457                 if (report_status)
 458                         report(unpack_status);
 459         }
 460         return 0;
 461 }