diff options
Diffstat (limited to 'src/backend/utils/init/miscinit.c')
| -rw-r--r-- | src/backend/utils/init/miscinit.c | 115 |
1 files changed, 103 insertions, 12 deletions
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c index f8f08f3f88b..03b28c3604a 100644 --- a/src/backend/utils/init/miscinit.c +++ b/src/backend/utils/init/miscinit.c @@ -89,6 +89,100 @@ SetDatabasePath(const char *path) } /* + * Validate the proposed data directory. + * + * Also initialize file and directory create modes and mode mask. + */ +void +checkDataDir(void) +{ + struct stat stat_buf; + + Assert(DataDir); + + if (stat(DataDir, &stat_buf) != 0) + { + if (errno == ENOENT) + ereport(FATAL, + (errcode_for_file_access(), + errmsg("data directory \"%s\" does not exist", + DataDir))); + else + ereport(FATAL, + (errcode_for_file_access(), + errmsg("could not read permissions of directory \"%s\": %m", + DataDir))); + } + + /* eventual chdir would fail anyway, but let's test ... */ + if (!S_ISDIR(stat_buf.st_mode)) + ereport(FATAL, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("specified data directory \"%s\" is not a directory", + DataDir))); + + /* + * Check that the directory belongs to my userid; if not, reject. + * + * This check is an essential part of the interlock that prevents two + * postmasters from starting in the same directory (see CreateLockFile()). + * Do not remove or weaken it. + * + * XXX can we safely enable this check on Windows? + */ +#if !defined(WIN32) && !defined(__CYGWIN__) + if (stat_buf.st_uid != geteuid()) + ereport(FATAL, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("data directory \"%s\" has wrong ownership", + DataDir), + errhint("The server must be started by the user that owns the data directory."))); +#endif + + /* + * Check if the directory has correct permissions. If not, reject. + * + * Only two possible modes are allowed, 0700 and 0750. The latter mode + * indicates that group read/execute should be allowed on all newly + * created files and directories. + * + * XXX temporarily suppress check when on Windows, because there may not + * be proper support for Unix-y file permissions. Need to think of a + * reasonable check to apply on Windows. + */ +#if !defined(WIN32) && !defined(__CYGWIN__) + if (stat_buf.st_mode & PG_MODE_MASK_GROUP) + ereport(FATAL, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("data directory \"%s\" has invalid permissions", + DataDir), + errdetail("Permissions should be u=rwx (0700) or u=rwx,g=rx (0750)."))); +#endif + + /* + * Reset creation modes and mask based on the mode of the data directory. + * + * The mask was set earlier in startup to disallow group permissions on + * newly created files and directories. However, if group read/execute + * are present on the data directory then modify the create modes and mask + * to allow group read/execute on newly created files and directories and + * set the data_directory_mode GUC. + * + * Suppress when on Windows, because there may not be proper support for + * Unix-y file permissions. + */ +#if !defined(WIN32) && !defined(__CYGWIN__) + SetDataDirectoryCreatePerm(stat_buf.st_mode); + + umask(pg_mode_mask); + data_directory_mode = pg_dir_create_mode; +#endif + + /* Check for PG_VERSION */ + ValidatePgVersion(DataDir); +} + +/* * Set data directory, but make sure it's an absolute path. Use this, * never set DataDir directly. */ @@ -829,7 +923,7 @@ CreateLockFile(const char *filename, bool amPostmaster, /* * Try to create the lock file --- O_EXCL makes this atomic. * - * Think not to make the file protection weaker than 0600. See + * Think not to make the file protection weaker than 0600/0640. See * comments below. */ fd = open(filename, O_RDWR | O_CREAT | O_EXCL, pg_file_create_mode); @@ -899,17 +993,14 @@ CreateLockFile(const char *filename, bool amPostmaster, * implies that the existing process has a different userid than we * do, which means it cannot be a competing postmaster. A postmaster * cannot successfully attach to a data directory owned by a userid - * other than its own. (This is now checked directly in - * checkDataDir(), but has been true for a long time because of the - * restriction that the data directory isn't group- or - * world-accessible.) Also, since we create the lockfiles mode 600, - * we'd have failed above if the lockfile belonged to another userid - * --- which means that whatever process kill() is reporting about - * isn't the one that made the lockfile. (NOTE: this last - * consideration is the only one that keeps us from blowing away a - * Unix socket file belonging to an instance of Postgres being run by - * someone else, at least on machines where /tmp hasn't got a - * stickybit.) + * other than its own, as enforced in checkDataDir(). Also, since we + * create the lockfiles mode 0600/0640, we'd have failed above if the + * lockfile belonged to another userid --- which means that whatever + * process kill() is reporting about isn't the one that made the + * lockfile. (NOTE: this last consideration is the only one that + * keeps us from blowing away a Unix socket file belonging to an + * instance of Postgres being run by someone else, at least on + * machines where /tmp hasn't got a stickybit.) */ if (other_pid != my_pid && other_pid != my_p_pid && other_pid != my_gp_pid) |