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 unpack_limit = 100;
  14 static int report_status;
  15
  16 static char capabilities[] = " report-status delete-refs ";
  17 static int capabilities_sent;
  18
  19 static int receive_pack_config(const char *var, const char *value)
  20 {
  21         git_default_config(var, value);
  22
  23         if (strcmp(var, "receive.denynonfastforwards") == 0)
  24         {
  25                 deny_non_fast_forwards = git_config_bool(var, value);
  26                 return 0;
  27         }
  28
  29         if (strcmp(var, "receive.unpacklimit") == 0)
  30         {
  31                 unpack_limit = git_config_int(var, value);
  32                 return 0;
  33         }
  34
  35         return 0;
  36 }
  37
  38 static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  39 {
  40         if (capabilities_sent)
  41                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  42         else
  43                 packet_write(1, "%s %s%c%s\n",
  44                              sha1_to_hex(sha1), path, 0, capabilities);
  45         capabilities_sent = 1;
  46         return 0;
  47 }
  48
  49 static void write_head_info(void)
  50 {
  51         for_each_ref(show_ref, NULL);
  52         if (!capabilities_sent)
  53                 show_ref("capabilities^{}", null_sha1, 0, NULL);
  54
  55 }
  56
  57 struct command {
  58         struct command *next;
  59         const char *error_string;
  60         unsigned char old_sha1[20];
  61         unsigned char new_sha1[20];
  62         char ref_name[FLEX_ARRAY]; /* more */
  63 };
  64
  65 static struct command *commands;
  66
  67 static char update_hook[] = "hooks/update";
  68
  69 static int run_update_hook(const char *refname,
  70                            char *old_hex, char *new_hex)
  71 {
  72         int code;
  73
  74         if (access(update_hook, X_OK) < 0)
  75                 return 0;
  76         code = run_command_opt(RUN_COMMAND_NO_STDIN
  77                 | RUN_COMMAND_STDOUT_TO_STDERR,
  78                 update_hook, refname, old_hex, new_hex, NULL);
  79         switch (code) {
  80         case 0:
  81                 return 0;
  82         case -ERR_RUN_COMMAND_FORK:
  83                 return error("hook fork failed");
  84         case -ERR_RUN_COMMAND_EXEC:
  85                 return error("hook execute failed");
  86         case -ERR_RUN_COMMAND_WAITPID:
  87                 return error("waitpid failed");
  88         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  89                 return error("waitpid is confused");
  90         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  91                 return error("%s died of signal", update_hook);
  92         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  93                 return error("%s died strangely", update_hook);
  94         default:
  95                 error("%s exited with error code %d", update_hook, -code);
  96                 return -code;
  97         }
  98 }
  99
 100 static int update(struct command *cmd)
 101 {
 102         const char *name = cmd->ref_name;
 103         unsigned char *old_sha1 = cmd->old_sha1;
 104         unsigned char *new_sha1 = cmd->new_sha1;
 105         char new_hex[41], old_hex[41];
 106         struct ref_lock *lock;
 107
 108         cmd->error_string = NULL;
 109         if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 110                 cmd->error_string = "funny refname";
 111                 return error("refusing to create funny ref '%s' locally",
 112                              name);
 113         }
 114
 115         strcpy(new_hex, sha1_to_hex(new_sha1));
 116         strcpy(old_hex, sha1_to_hex(old_sha1));
 117
 118         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 119                 cmd->error_string = "bad pack";
 120                 return error("unpack should have generated %s, "
 121                              "but I can't find it!", new_hex);
 122         }
 123         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 124             !is_null_sha1(old_sha1) &&
 125             !strncmp(name, "refs/heads/", 11)) {
 126                 struct commit *old_commit, *new_commit;
 127                 struct commit_list *bases, *ent;
 128
 129                 old_commit = (struct commit *)parse_object(old_sha1);
 130                 new_commit = (struct commit *)parse_object(new_sha1);
 131                 bases = get_merge_bases(old_commit, new_commit, 1);
 132                 for (ent = bases; ent; ent = ent->next)
 133                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 134                                 break;
 135                 free_commit_list(bases);
 136                 if (!ent)
 137                         return error("denying non-fast forward;"
 138                                      " you should pull first");
 139         }
 140         if (run_update_hook(name, old_hex, new_hex)) {
 141                 cmd->error_string = "hook declined";
 142                 return error("hook declined to update %s", name);
 143         }
 144
 145         if (is_null_sha1(new_sha1)) {
 146                 if (delete_ref(name, old_sha1)) {
 147                         cmd->error_string = "failed to delete";
 148                         return error("failed to delete %s", name);
 149                 }
 150                 fprintf(stderr, "%s: %s -> deleted\n", name, old_hex);
 151         }
 152         else {
 153                 lock = lock_any_ref_for_update(name, old_sha1);
 154                 if (!lock) {
 155                         cmd->error_string = "failed to lock";
 156                         return error("failed to lock %s", name);
 157                 }
 158                 write_ref_sha1(lock, new_sha1, "push");
 159                 fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 160         }
 161         return 0;
 162 }
 163
 164 static char update_post_hook[] = "hooks/post-update";
 165
 166 static void run_update_post_hook(struct command *cmd)
 167 {
 168         struct command *cmd_p;
 169         int argc;
 170         const char **argv;
 171
 172         if (access(update_post_hook, X_OK) < 0)
 173                 return;
 174         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 175                 if (cmd_p->error_string)
 176                         continue;
 177                 argc++;
 178         }
 179         argv = xmalloc(sizeof(*argv) * (1 + argc));
 180         argv[0] = update_post_hook;
 181
 182         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 183                 char *p;
 184                 if (cmd_p->error_string)
 185                         continue;
 186                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 187                 strcpy(p, cmd_p->ref_name);
 188                 argv[argc] = p;
 189                 argc++;
 190         }
 191         argv[argc] = NULL;
 192         run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
 193                 | RUN_COMMAND_STDOUT_TO_STDERR);
 194 }
 195
 196 /*
 197  * This gets called after(if) we've successfully
 198  * unpacked the data payload.
 199  */
 200 static void execute_commands(void)
 201 {
 202         struct command *cmd = commands;
 203
 204         while (cmd) {
 205                 update(cmd);
 206                 cmd = cmd->next;
 207         }
 208         run_update_post_hook(commands);
 209 }
 210
 211 static void read_head_info(void)
 212 {
 213         struct command **p = &commands;
 214         for (;;) {
 215                 static char line[1000];
 216                 unsigned char old_sha1[20], new_sha1[20];
 217                 struct command *cmd;
 218                 char *refname;
 219                 int len, reflen;
 220
 221                 len = packet_read_line(0, line, sizeof(line));
 222                 if (!len)
 223                         break;
 224                 if (line[len-1] == '\n')
 225                         line[--len] = 0;
 226                 if (len < 83 ||
 227                     line[40] != ' ' ||
 228                     line[81] != ' ' ||
 229                     get_sha1_hex(line, old_sha1) ||
 230                     get_sha1_hex(line + 41, new_sha1))
 231                         die("protocol error: expected old/new/ref, got '%s'",
 232                             line);
 233
 234                 refname = line + 82;
 235                 reflen = strlen(refname);
 236                 if (reflen + 82 < len) {
 237                         if (strstr(refname + reflen + 1, "report-status"))
 238                                 report_status = 1;
 239                 }
 240                 cmd = xmalloc(sizeof(struct command) + len - 80);
 241                 hashcpy(cmd->old_sha1, old_sha1);
 242                 hashcpy(cmd->new_sha1, new_sha1);
 243                 memcpy(cmd->ref_name, line + 82, len - 81);
 244                 cmd->error_string = "n/a (unpacker error)";
 245                 cmd->next = NULL;
 246                 *p = cmd;
 247                 p = &cmd->next;
 248         }
 249 }
 250
 251 static const char *parse_pack_header(struct pack_header *hdr)
 252 {
 253         char *c = (char*)hdr;
 254         ssize_t remaining = sizeof(struct pack_header);
 255         do {
 256                 ssize_t r = xread(0, c, remaining);
 257                 if (r <= 0)
 258                         return "eof before pack header was fully read";
 259                 remaining -= r;
 260                 c += r;
 261         } while (remaining > 0);
 262         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 263                 return "protocol error (pack signature mismatch detected)";
 264         if (!pack_version_ok(hdr->hdr_version))
 265                 return "protocol error (pack version unsupported)";
 266         return NULL;
 267 }
 268
 269 static const char *pack_lockfile;
 270
 271 static const char *unpack(void)
 272 {
 273         struct pack_header hdr;
 274         const char *hdr_err;
 275         char hdr_arg[38];
 276
 277         hdr_err = parse_pack_header(&hdr);
 278         if (hdr_err)
 279                 return hdr_err;
 280         snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 281                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 282
 283         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 284                 int code;
 285                 const char *unpacker[3];
 286                 unpacker[0] = "unpack-objects";
 287                 unpacker[1] = hdr_arg;
 288                 unpacker[2] = NULL;
 289                 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
 290                 switch (code) {
 291                 case 0:
 292                         return NULL;
 293                 case -ERR_RUN_COMMAND_FORK:
 294                         return "unpack fork failed";
 295                 case -ERR_RUN_COMMAND_EXEC:
 296                         return "unpack execute failed";
 297                 case -ERR_RUN_COMMAND_WAITPID:
 298                         return "waitpid failed";
 299                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 300                         return "waitpid is confused";
 301                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 302                         return "unpacker died of signal";
 303                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 304                         return "unpacker died strangely";
 305                 default:
 306                         return "unpacker exited with error code";
 307                 }
 308         } else {
 309                 const char *keeper[6];
 310                 int fd[2], s, len, status;
 311                 pid_t pid;
 312                 char keep_arg[256];
 313                 char packname[46];
 314
 315                 s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
 316                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 317                         strcpy(keep_arg + s, "localhost");
 318
 319                 keeper[0] = "index-pack";
 320                 keeper[1] = "--stdin";
 321                 keeper[2] = "--fix-thin";
 322                 keeper[3] = hdr_arg;
 323                 keeper[4] = keep_arg;
 324                 keeper[5] = NULL;
 325
 326                 if (pipe(fd) < 0)
 327                         return "index-pack pipe failed";
 328                 pid = fork();
 329                 if (pid < 0)
 330                         return "index-pack fork failed";
 331                 if (!pid) {
 332                         dup2(fd[1], 1);
 333                         close(fd[1]);
 334                         close(fd[0]);
 335                         execv_git_cmd(keeper);
 336                         die("execv of index-pack failed");
 337                 }
 338                 close(fd[1]);
 339
 340                 /*
 341                  * The first thing we expects from index-pack's output
 342                  * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
 343                  * %40s is the newly created pack SHA1 name.  In the "keep"
 344                  * case, we need it to remove the corresponding .keep file
 345                  * later on.  If we don't get that then tough luck with it.
 346                  */
 347                 for (len = 0;
 348                      len < 46 && (s = xread(fd[0], packname+len, 46-len)) > 0;
 349                      len += s);
 350                 close(fd[0]);
 351                 if (len == 46 && packname[45] == '\n' &&
 352                     memcmp(packname, "keep\t", 5) == 0) {
 353                         char path[PATH_MAX];
 354                         packname[45] = 0;
 355                         snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
 356                                  get_object_directory(), packname + 5);
 357                         pack_lockfile = xstrdup(path);
 358                 }
 359
 360                 /* Then wrap our index-pack process. */
 361                 while (waitpid(pid, &status, 0) < 0)
 362                         if (errno != EINTR)
 363                                 return "waitpid failed";
 364                 if (WIFEXITED(status)) {
 365                         int code = WEXITSTATUS(status);
 366                         if (code)
 367                                 return "index-pack exited with error code";
 368                         reprepare_packed_git();
 369                         return NULL;
 370                 }
 371                 return "index-pack abnormal exit";
 372         }
 373 }
 374
 375 static void report(const char *unpack_status)
 376 {
 377         struct command *cmd;
 378         packet_write(1, "unpack %s\n",
 379                      unpack_status ? unpack_status : "ok");
 380         for (cmd = commands; cmd; cmd = cmd->next) {
 381                 if (!cmd->error_string)
 382                         packet_write(1, "ok %s\n",
 383                                      cmd->ref_name);
 384                 else
 385                         packet_write(1, "ng %s %s\n",
 386                                      cmd->ref_name, cmd->error_string);
 387         }
 388         packet_flush(1);
 389 }
 390
 391 static int delete_only(struct command *cmd)
 392 {
 393         while (cmd) {
 394                 if (!is_null_sha1(cmd->new_sha1))
 395                         return 0;
 396                 cmd = cmd->next;
 397         }
 398         return 1;
 399 }
 400
 401 int main(int argc, char **argv)
 402 {
 403         int i;
 404         char *dir = NULL;
 405
 406         argv++;
 407         for (i = 1; i < argc; i++) {
 408                 char *arg = *argv++;
 409
 410                 if (*arg == '-') {
 411                         /* Do flag handling here */
 412                         usage(receive_pack_usage);
 413                 }
 414                 if (dir)
 415                         usage(receive_pack_usage);
 416                 dir = arg;
 417         }
 418         if (!dir)
 419                 usage(receive_pack_usage);
 420
 421         if (!enter_repo(dir, 0))
 422                 die("'%s': unable to chdir or not a git archive", dir);
 423
 424         setup_ident();
 425         /* don't die if gecos is empty */
 426         ignore_missing_committer_name();
 427         git_config(receive_pack_config);
 428
 429         write_head_info();
 430
 431         /* EOF */
 432         packet_flush(1);
 433
 434         read_head_info();
 435         if (commands) {
 436                 const char *unpack_status = NULL;
 437
 438                 if (!delete_only(commands))
 439                         unpack_status = unpack();
 440                 if (!unpack_status)
 441                         execute_commands();
 442                 if (pack_lockfile)
 443                         unlink(pack_lockfile);
 444                 if (report_status)
 445                         report(unpack_status);
 446         }
 447         return 0;
 448 }