diff options
Diffstat (limited to 'source3/lib')
| -rw-r--r-- | source3/lib/util_tdb.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/source3/lib/util_tdb.c b/source3/lib/util_tdb.c index 6d783198d6..cb53b7f2e3 100644 --- a/source3/lib/util_tdb.c +++ b/source3/lib/util_tdb.c @@ -980,3 +980,206 @@ NTSTATUS map_nt_error_from_tdb(enum TDB_ERROR err) return NT_STATUS_INTERNAL_ERROR; } + + +/********************************************************************* + * the following is a generic validation mechanism for tdbs. + *********************************************************************/ + +/* + * internal validation function, executed by the child. + */ +static int tdb_validate_child(const char *tdb_path, + tdb_validate_data_func validate_fn, + int pfd) +{ + int ret = -1; + int tfd = -1; + int num_entries = 0; + TDB_CONTEXT *tdb = NULL; + struct tdb_validation_status v_status; + + v_status.tdb_error = False; + v_status.bad_freelist = False; + v_status.bad_entry = False; + v_status.unknown_key = False; + v_status.success = True; + + tdb = tdb_open_log(tdb_path, + WINBINDD_CACHE_TDB_DEFAULT_HASH_SIZE, + lp_winbind_offline_logon() + ? TDB_DEFAULT + : (TDB_DEFAULT | TDB_CLEAR_IF_FIRST), + O_RDWR|O_CREAT, 0600); + if (!tdb) { + v_status.tdb_error = True; + v_status.success = False; + goto out; + } + + tfd = tdb_fd(tdb); + + /* Check the cache freelist is good. */ + if (tdb_validate_freelist(tdb, &num_entries) == -1) { + DEBUG(0,("tdb_validate_child: bad freelist in cache %s\n", + tdb_path)); + v_status.bad_freelist = True; + v_status.success = False; + goto out; + } + + DEBUG(10,("tdb_validate_child: cache %s freelist has %d entries\n", + tdb_path, num_entries)); + + /* Now traverse the cache to validate it. */ + num_entries = tdb_traverse(tdb, validate_fn, (void *)&v_status); + if (num_entries == -1 || !(v_status.success)) { + DEBUG(0,("tdb_validate_child: cache %s traverse failed\n", + tdb_path)); + if (!(v_status.success)) { + if (v_status.bad_entry) { + DEBUGADD(0, (" -> bad entry found\n")); + } + if (v_status.unknown_key) { + DEBUGADD(0, (" -> unknown key encountered\n")); + } + } + goto out; + } + + DEBUG(10,("tdb_validate_child: cache %s is good " + "with %d entries\n", tdb_path, num_entries)); + ret = 0; /* Cache is good. */ + +out: + if (tdb) { + if (ret == 0) { + tdb_close(tdb); + } + else if (tfd != -1) { + close(tfd); + } + } + + DEBUG(10, ("tdb_validate_child: writing status to pipe\n")); + write (pfd, (const char *)&v_status, sizeof(v_status)); + close(pfd); + + return ret; +} + +int tdb_validate(const char *tdb_path, tdb_validate_data_func validate_fn) +{ + pid_t child_pid = -1; + int child_status = 0; + int wait_pid = 0; + int ret = -1; + int pipe_fds[2]; + struct tdb_validation_status v_status; + int bytes_read = 0; + + /* fork and let the child do the validation. + * benefit: no need to twist signal handlers and panic functions. + * just let the child panic. we catch the signal. + * communicate the extended status struct over a pipe. */ + + if (pipe(pipe_fds) != 0) { + DEBUG(0, ("tdb_validate: unable to create pipe, " + "error %s", strerror(errno))); + smb_panic("winbind_validate_cache: unable to create pipe."); + } + + DEBUG(10, ("tdb_validate: forking to let child do validation.\n")); + child_pid = sys_fork(); + if (child_pid == 0) { + DEBUG(10, ("tdb_validate (validation child): created\n")); + close(pipe_fds[0]); /* close reading fd */ + DEBUG(10, ("tdb_validate (validation child): " + "calling tdb_validate_child\n")); + exit(tdb_validate_child(tdb_path, validate_fn, pipe_fds[1])); + } + else if (child_pid < 0) { + smb_panic("tdb_validate: fork for validation failed."); + } + + /* parent */ + + DEBUG(10, ("tdb_validate: fork succeeded, child PID = %d\n", + child_pid)); + close(pipe_fds[1]); /* close writing fd */ + + v_status.success = True; + v_status.bad_entry = False; + v_status.unknown_key = False; + + DEBUG(10, ("tdb_validate: reading from pipe.\n")); + bytes_read = read(pipe_fds[0], (void *)&v_status, sizeof(v_status)); + close(pipe_fds[0]); + + if (bytes_read != sizeof(v_status)) { + DEBUG(10, ("tdb_validate: read %d bytes from pipe " + "but expected %d", bytes_read, (int)sizeof(v_status))); + DEBUGADD(10, (" -> assuming child crashed\n")); + v_status.success = False; + } + else { + DEBUG(10, ("tdb_validate: read status from child\n")); + DEBUGADD(10, (" * tdb error: %s\n", v_status.tdb_error ? "yes" : "no")); + DEBUGADD(10, (" * bad freelist: %s\n", v_status.bad_freelist ? "yes" : "no")); + DEBUGADD(10, (" * bad entry: %s\n", v_status.bad_entry ? "yes" : "no")); + DEBUGADD(10, (" * unknown key: %s\n", v_status.unknown_key ? "yes" : "no")); + DEBUGADD(10, (" => overall success: %s\n", v_status.success ? "yes" : "no")); + } + + if (!v_status.success) { + DEBUG(10, ("tdb_validate: validation not successful.\n")); + DEBUGADD(10, ("removing tdb %s.\n", tdb_path)); + unlink(tdb_path); + } + + DEBUG(10, ("tdb_validate: waiting for child to finish...\n")); + while ((wait_pid = sys_waitpid(child_pid, &child_status, 0)) < 0) { + if (errno == EINTR) { + DEBUG(10, ("tdb_validate: got signal during " + "waitpid, retrying\n")); + errno = 0; + continue; + } + DEBUG(0, ("tdb_validate: waitpid failed with " + "errno %s\n", strerror(errno))); + smb_panic("tdb_validate: waitpid failed."); + } + if (wait_pid != child_pid) { + DEBUG(0, ("tdb_validate: waitpid returned pid %d, " + "but %d was expexted\n", wait_pid, child_pid)); + smb_panic("tdb_validate: waitpid returned " + "unexpected PID."); + } + + + DEBUG(10, ("tdb_validate: validating child returned.\n")); + if (WIFEXITED(child_status)) { + DEBUG(10, ("tdb_validate: child exited, code %d.\n", + WEXITSTATUS(child_status))); + ret = WEXITSTATUS(child_status); + } + if (WIFSIGNALED(child_status)) { + DEBUG(10, ("tdb_validate: child terminated " + "by signal %d\n", WTERMSIG(child_status))); +#ifdef WCOREDUMP + if (WCOREDUMP(child_status)) { + DEBUGADD(10, ("core dumped\n")); + } +#endif + ret = WTERMSIG(child_status); + } + if (WIFSTOPPED(child_status)) { + DEBUG(10, ("tdb_validate: child was stopped " + "by signal %d\n", + WSTOPSIG(child_status))); + ret = WSTOPSIG(child_status); + } + + return ret; +} + |