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 #include <sys/wait.h>
  10
  11 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
  12
  13 static int deny_non_fast_forwards = 0;
  14 static int unpack_limit = 100;
  15 static int report_status;
  16
  17 static char capabilities[] = " report-status delete-refs ";
  18 static int capabilities_sent;
  19
  20 static int receive_pack_config(const char *var, const char *value)
  21 {
  22         git_default_config(var, value);
  23
  24         if (strcmp(var, "receive.denynonfastforwards") == 0)
  25         {
  26                 deny_non_fast_forwards = git_config_bool(var, value);
  27                 return 0;
  28         }
  29
  30         if (strcmp(var, "receive.unpacklimit") == 0)
  31         {
  32                 unpack_limit = git_config_int(var, value);
  33                 return 0;
  34         }
  35
  36         return 0;
  37 }
  38
  39 static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  40 {
  41         if (capabilities_sent)
  42                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  43         else
  44                 packet_write(1, "%s %s%c%s\n",
  45                              sha1_to_hex(sha1), path, 0, capabilities);
  46         capabilities_sent = 1;
  47         return 0;
  48 }
  49
  50 static void write_head_info(void)
  51 {
  52         for_each_ref(show_ref, NULL);
  53         if (!capabilities_sent)
  54                 show_ref("capabilities^{}", null_sha1, 0, NULL);
  55
  56 }
  57
  58 struct command {
  59         struct command *next;
  60         const char *error_string;
  61         unsigned char old_sha1[20];
  62         unsigned char new_sha1[20];
  63         char ref_name[FLEX_ARRAY]; /* more */
  64 };
  65
  66 static struct command *commands;
  67
  68 static char update_hook[] = "hooks/update";
  69
  70 static int run_update_hook(const char *refname,
  71                            char *old_hex, char *new_hex)
  72 {
  73         int code;
  74
  75         if (access(update_hook, X_OK) < 0)
  76                 return 0;
  77         code = run_command(update_hook, refname, old_hex, new_hex, NULL);
  78         switch (code) {
  79         case 0:
  80                 return 0;
  81         case -ERR_RUN_COMMAND_FORK:
  82                 return error("hook fork failed");
  83         case -ERR_RUN_COMMAND_EXEC:
  84                 return error("hook execute failed");
  85         case -ERR_RUN_COMMAND_WAITPID:
  86                 return error("waitpid failed");
  87         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  88                 return error("waitpid is confused");
  89         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  90                 return error("%s died of signal", update_hook);
  91         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  92                 return error("%s died strangely", update_hook);
  93         default:
  94                 error("%s exited with error code %d", update_hook, -code);
  95                 return -code;
  96         }
  97 }
  98
  99 static int update(struct command *cmd)
 100 {
 101         const char *name = cmd->ref_name;
 102         unsigned char *old_sha1 = cmd->old_sha1;
 103         unsigned char *new_sha1 = cmd->new_sha1;
 104         char new_hex[41], old_hex[41];
 105         struct ref_lock *lock;
 106
 107         cmd->error_string = NULL;
 108         if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 109                 cmd->error_string = "funny refname";
 110                 return error("refusing to create funny ref '%s' locally",
 111                              name);
 112         }
 113
 114         strcpy(new_hex, sha1_to_hex(new_sha1));
 115         strcpy(old_hex, sha1_to_hex(old_sha1));
 116
 117         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 118                 cmd->error_string = "bad pack";
 119                 return error("unpack should have generated %s, "
 120                              "but I can't find it!", new_hex);
 121         }
 122         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 123             !is_null_sha1(old_sha1) &&
 124             !strncmp(name, "refs/heads/", 11)) {
 125                 struct commit *old_commit, *new_commit;
 126                 struct commit_list *bases, *ent;
 127
 128                 old_commit = (struct commit *)parse_object(old_sha1);
 129                 new_commit = (struct commit *)parse_object(new_sha1);
 130                 bases = get_merge_bases(old_commit, new_commit, 1);
 131                 for (ent = bases; ent; ent = ent->next)
 132                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 133                                 break;
 134                 free_commit_list(bases);
 135                 if (!ent)
 136                         return error("denying non-fast forward;"
 137                                      " you should pull first");
 138         }
 139         if (run_update_hook(name, old_hex, new_hex)) {
 140                 cmd->error_string = "hook declined";
 141                 return error("hook declined to update %s", name);
 142         }
 143
 144         if (is_null_sha1(new_sha1)) {
 145                 if (delete_ref(name, old_sha1)) {
 146                         cmd->error_string = "failed to delete";
 147                         return error("failed to delete %s", name);
 148                 }
 149                 fprintf(stderr, "%s: %s -> deleted\n", name, old_hex);
 150         }
 151         else {
 152                 lock = lock_any_ref_for_update(name, old_sha1);
 153                 if (!lock) {
 154                         cmd->error_string = "failed to lock";
 155                         return error("failed to lock %s", name);
 156                 }
 157                 write_ref_sha1(lock, new_sha1, "push");
 158                 fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 159         }
 160         return 0;
 161 }
 162
 163 static char update_post_hook[] = "hooks/post-update";
 164
 165 static void run_update_post_hook(struct command *cmd)
 166 {
 167         struct command *cmd_p;
 168         int argc;
 169         const char **argv;
 170
 171         if (access(update_post_hook, X_OK) < 0)
 172                 return;
 173         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 174                 if (cmd_p->error_string)
 175                         continue;
 176                 argc++;
 177         }
 178         argv = xmalloc(sizeof(*argv) * (1 + argc));
 179         argv[0] = update_post_hook;
 180
 181         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 182                 char *p;
 183                 if (cmd_p->error_string)
 184                         continue;
 185                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 186                 strcpy(p, cmd_p->ref_name);
 187                 argv[argc] = p;
 188                 argc++;
 189         }
 190         argv[argc] = NULL;
 191         run_command_v_opt(argc, argv, RUN_COMMAND_NO_STDIO);
 192 }
 193
 194 /*
 195  * This gets called after(if) we've successfully
 196  * unpacked the data payload.
 197  */
 198 static void execute_commands(void)
 199 {
 200         struct command *cmd = commands;
 201
 202         while (cmd) {
 203                 update(cmd);
 204                 cmd = cmd->next;
 205         }
 206         run_update_post_hook(commands);
 207 }
 208
 209 static void read_head_info(void)
 210 {
 211         struct command **p = &commands;
 212         for (;;) {
 213                 static char line[1000];
 214                 unsigned char old_sha1[20], new_sha1[20];
 215                 struct command *cmd;
 216                 char *refname;
 217                 int len, reflen;
 218
 219                 len = packet_read_line(0, line, sizeof(line));
 220                 if (!len)
 221                         break;
 222                 if (line[len-1] == '\n')
 223                         line[--len] = 0;
 224                 if (len < 83 ||
 225                     line[40] != ' ' ||
 226                     line[81] != ' ' ||
 227                     get_sha1_hex(line, old_sha1) ||
 228                     get_sha1_hex(line + 41, new_sha1))
 229                         die("protocol error: expected old/new/ref, got '%s'",
 230                             line);
 231
 232                 refname = line + 82;
 233                 reflen = strlen(refname);
 234                 if (reflen + 82 < len) {
 235                         if (strstr(refname + reflen + 1, "report-status"))
 236                                 report_status = 1;
 237                 }
 238                 cmd = xmalloc(sizeof(struct command) + len - 80);
 239                 hashcpy(cmd->old_sha1, old_sha1);
 240                 hashcpy(cmd->new_sha1, new_sha1);
 241                 memcpy(cmd->ref_name, line + 82, len - 81);
 242                 cmd->error_string = "n/a (unpacker error)";
 243                 cmd->next = NULL;
 244                 *p = cmd;
 245                 p = &cmd->next;
 246         }
 247 }
 248
 249 static const char *parse_pack_header(struct pack_header *hdr)
 250 {
 251         char *c = (char*)hdr;
 252         ssize_t remaining = sizeof(struct pack_header);
 253         do {
 254                 ssize_t r = xread(0, c, remaining);
 255                 if (r <= 0)
 256                         return "eof before pack header was fully read";
 257                 remaining -= r;
 258                 c += r;
 259         } while (remaining > 0);
 260         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 261                 return "protocol error (pack signature mismatch detected)";
 262         if (!pack_version_ok(hdr->hdr_version))
 263                 return "protocol error (pack version unsupported)";
 264         return NULL;
 265 }
 266
 267 static const char *pack_lockfile;
 268
 269 static const char *unpack(void)
 270 {
 271         struct pack_header hdr;
 272         const char *hdr_err;
 273         char hdr_arg[38];
 274
 275         hdr_err = parse_pack_header(&hdr);
 276         if (hdr_err)
 277                 return hdr_err;
 278         snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 279                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 280
 281         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 282                 int code;
 283                 const char *unpacker[3];
 284                 unpacker[0] = "unpack-objects";
 285                 unpacker[1] = hdr_arg;
 286                 unpacker[2] = NULL;
 287                 code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
 288                 switch (code) {
 289                 case 0:
 290                         return NULL;
 291                 case -ERR_RUN_COMMAND_FORK:
 292                         return "unpack fork failed";
 293                 case -ERR_RUN_COMMAND_EXEC:
 294                         return "unpack execute failed";
 295                 case -ERR_RUN_COMMAND_WAITPID:
 296                         return "waitpid failed";
 297                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 298                         return "waitpid is confused";
 299                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 300                         return "unpacker died of signal";
 301                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 302                         return "unpacker died strangely";
 303                 default:
 304                         return "unpacker exited with error code";
 305                 }
 306         } else {
 307                 const char *keeper[6];
 308                 int fd[2], s, len, status;
 309                 pid_t pid;
 310                 char keep_arg[256];
 311                 char packname[46];
 312
 313                 s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
 314                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 315                         strcpy(keep_arg + s, "localhost");
 316
 317                 keeper[0] = "index-pack";
 318                 keeper[1] = "--stdin";
 319                 keeper[2] = "--fix-thin";
 320                 keeper[3] = hdr_arg;
 321                 keeper[4] = keep_arg;
 322                 keeper[5] = NULL;
 323
 324                 if (pipe(fd) < 0)
 325                         return "index-pack pipe failed";
 326                 pid = fork();
 327                 if (pid < 0)
 328                         return "index-pack fork failed";
 329                 if (!pid) {
 330                         dup2(fd[1], 1);
 331                         close(fd[1]);
 332                         close(fd[0]);
 333                         execv_git_cmd(keeper);
 334                         die("execv of index-pack failed");
 335                 }
 336                 close(fd[1]);
 337
 338                 /*
 339                  * The first thing we expects from index-pack's output
 340                  * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
 341                  * %40s is the newly created pack SHA1 name.  In the "keep"
 342                  * case, we need it to remove the corresponding .keep file
 343                  * later on.  If we don't get that then tough luck with it.
 344                  */
 345                 for (len = 0;
 346                      len < 46 && (s = xread(fd[0], packname+len, 46-len)) > 0;
 347                      len += s);
 348                 close(fd[0]);
 349                 if (len == 46 && packname[45] == '\n' &&
 350                     memcmp(packname, "keep\t", 5) == 0) {
 351                         char path[PATH_MAX];
 352                         packname[45] = 0;
 353                         snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
 354                                  get_object_directory(), packname + 5);
 355                         pack_lockfile = xstrdup(path);
 356                 }
 357
 358                 /* Then wrap our index-pack process. */
 359                 while (waitpid(pid, &status, 0) < 0)
 360                         if (errno != EINTR)
 361                                 return "waitpid failed";
 362                 if (WIFEXITED(status)) {
 363                         int code = WEXITSTATUS(status);
 364                         if (code)
 365                                 return "index-pack exited with error code";
 366                         reprepare_packed_git();
 367                         return NULL;
 368                 }
 369                 return "index-pack abnormal exit";
 370         }
 371 }
 372
 373 static void report(const char *unpack_status)
 374 {
 375         struct command *cmd;
 376         packet_write(1, "unpack %s\n",
 377                      unpack_status ? unpack_status : "ok");
 378         for (cmd = commands; cmd; cmd = cmd->next) {
 379                 if (!cmd->error_string)
 380                         packet_write(1, "ok %s\n",
 381                                      cmd->ref_name);
 382                 else
 383                         packet_write(1, "ng %s %s\n",
 384                                      cmd->ref_name, cmd->error_string);
 385         }
 386         packet_flush(1);
 387 }
 388
 389 static int delete_only(struct command *cmd)
 390 {
 391         while (cmd) {
 392                 if (!is_null_sha1(cmd->new_sha1))
 393                         return 0;
 394                 cmd = cmd->next;
 395         }
 396         return 1;
 397 }
 398
 399 int main(int argc, char **argv)
 400 {
 401         int i;
 402         char *dir = NULL;
 403
 404         argv++;
 405         for (i = 1; i < argc; i++) {
 406                 char *arg = *argv++;
 407
 408                 if (*arg == '-') {
 409                         /* Do flag handling here */
 410                         usage(receive_pack_usage);
 411                 }
 412                 if (dir)
 413                         usage(receive_pack_usage);
 414                 dir = arg;
 415         }
 416         if (!dir)
 417                 usage(receive_pack_usage);
 418
 419         if (!enter_repo(dir, 0))
 420                 die("'%s': unable to chdir or not a git archive", dir);
 421
 422         setup_ident();
 423         git_config(receive_pack_config);
 424
 425         write_head_info();
 426
 427         /* EOF */
 428         packet_flush(1);
 429
 430         read_head_info();
 431         if (commands) {
 432                 const char *unpack_status = NULL;
 433
 434                 if (!delete_only(commands))
 435                         unpack_status = unpack();
 436                 if (!unpack_status)
 437                         execute_commands();
 438                 if (pack_lockfile)
 439                         unlink(pack_lockfile);
 440                 if (report_status)
 441                         report(unpack_status);
 442         }
 443         return 0;
 444 }