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-rw-r--r--source3/lib/tdb_validate.c502
1 files changed, 502 insertions, 0 deletions
diff --git a/source3/lib/tdb_validate.c b/source3/lib/tdb_validate.c
new file mode 100644
index 0000000000..1f5dfe4d25
--- /dev/null
+++ b/source3/lib/tdb_validate.c
@@ -0,0 +1,502 @@
+/*
+ * Unix SMB/CIFS implementation.
+ *
+ * A general tdb content validation mechanism
+ *
+ * Copyright (C) Michael Adam 2007
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "tdb_validate.h"
+#include "includes.h"
+
+/*
+ * internal validation function, executed by the child.
+ */
+static int tdb_validate_child(struct tdb_context *tdb,
+ tdb_validate_data_func validate_fn)
+{
+ int ret = 1;
+ int num_entries = 0;
+ 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;
+
+ if (!tdb) {
+ v_status.tdb_error = True;
+ v_status.success = False;
+ goto out;
+ }
+
+ /* Check if the tdb's freelist is good. */
+ if (tdb_validate_freelist(tdb, &num_entries) == -1) {
+ v_status.bad_freelist = True;
+ v_status.success = False;
+ goto out;
+ }
+
+ DEBUG(10,("tdb_validate_child: tdb %s freelist has %d entries\n",
+ tdb_name(tdb), num_entries));
+
+ /* Now traverse the tdb to validate it. */
+ num_entries = tdb_traverse(tdb, validate_fn, (void *)&v_status);
+ if (!v_status.success) {
+ goto out;
+ } else if (num_entries == -1) {
+ v_status.tdb_error = True;
+ v_status.success = False;
+ goto out;
+ }
+
+ DEBUG(10,("tdb_validate_child: tdb %s is good with %d entries\n",
+ tdb_name(tdb), num_entries));
+ ret = 0; /* Cache is good. */
+
+out:
+ DEBUG(10, ("tdb_validate_child: summary of validation status:\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"));
+
+ return ret;
+}
+
+/*
+ * tdb validation function.
+ * returns 0 if tdb is ok, != 0 if it isn't.
+ * this function expects an opened tdb.
+ */
+int tdb_validate(struct tdb_context *tdb, tdb_validate_data_func validate_fn)
+{
+ pid_t child_pid = -1;
+ int child_status = 0;
+ int wait_pid = 0;
+ int ret = 1;
+
+ if (tdb == NULL) {
+ DEBUG(1, ("Error: tdb_validate called with tdb == NULL\n"));
+ return ret;
+ }
+
+ DEBUG(5, ("tdb_validate called for tdb '%s'\n", tdb_name(tdb)));
+
+ /* 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. */
+
+ DEBUG(10, ("tdb_validate: forking to let child do validation.\n"));
+ child_pid = sys_fork();
+ if (child_pid == 0) {
+ /* child code */
+ DEBUG(10, ("tdb_validate (validation child): created\n"));
+ DEBUG(10, ("tdb_validate (validation child): "
+ "calling tdb_validate_child\n"));
+ exit(tdb_validate_child(tdb, validate_fn));
+ }
+ else if (child_pid < 0) {
+ DEBUG(1, ("tdb_validate: fork for validation failed.\n"));
+ goto done;
+ }
+
+ /* parent */
+
+ DEBUG(10, ("tdb_validate: fork succeeded, child PID = %d\n",child_pid));
+
+ 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(1, ("tdb_validate: waitpid failed with error '%s'.\n",
+ strerror(errno)));
+ goto done;
+ }
+ if (wait_pid != child_pid) {
+ DEBUG(1, ("tdb_validate: waitpid returned pid %d, "
+ "but %d was expected\n", wait_pid, child_pid));
+ goto done;
+ }
+
+ 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);
+ }
+
+done:
+ DEBUG(5, ("tdb_validate returning code '%d' for tdb '%s'\n", ret,
+ tdb_name(tdb)));
+
+ return ret;
+}
+
+/*
+ * tdb validation function.
+ * returns 0 if tdb is ok, != 0 if it isn't.
+ * this is a wrapper around the actual validation function that opens and closes
+ * the tdb.
+ */
+int tdb_validate_open(const char *tdb_path, tdb_validate_data_func validate_fn)
+{
+ TDB_CONTEXT *tdb = NULL;
+ int ret = 1;
+
+ DEBUG(5, ("tdb_validate_open called for tdb '%s'\n", tdb_path));
+
+ tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDONLY, 0);
+ if (!tdb) {
+ DEBUG(1, ("Error opening tdb %s\n", tdb_path));
+ return ret;
+ }
+
+ ret = tdb_validate(tdb, validate_fn);
+ tdb_close(tdb);
+ return ret;
+}
+
+/*
+ * tdb backup function and helpers for tdb_validate wrapper with backup
+ * handling.
+ */
+
+/* this structure eliminates the need for a global overall status for
+ * the traverse-copy */
+struct tdb_copy_data {
+ struct tdb_context *dst;
+ bool success;
+};
+
+static int traverse_copy_fn(struct tdb_context *tdb, TDB_DATA key,
+ TDB_DATA dbuf, void *private_data)
+{
+ struct tdb_copy_data *data = (struct tdb_copy_data *)private_data;
+
+ if (tdb_store(data->dst, key, dbuf, TDB_INSERT) != 0) {
+ DEBUG(4, ("Failed to insert into %s: %s\n", tdb_name(data->dst),
+ strerror(errno)));
+ data->success = False;
+ return 1;
+ }
+ return 0;
+}
+
+static int tdb_copy(struct tdb_context *src, struct tdb_context *dst)
+{
+ struct tdb_copy_data data;
+ int count;
+
+ data.dst = dst;
+ data.success = True;
+
+ count = tdb_traverse(src, traverse_copy_fn, (void *)(&data));
+ if ((count < 0) || (data.success == False)) {
+ return -1;
+ }
+ return count;
+}
+
+static int tdb_verify_basic(struct tdb_context *tdb)
+{
+ return tdb_traverse(tdb, NULL, NULL);
+}
+
+/* this backup function is essentially taken from lib/tdb/tools/tdbbackup.tdb
+ */
+static int tdb_backup(TALLOC_CTX *ctx, const char *src_path,
+ const char *dst_path, int hash_size)
+{
+ struct tdb_context *src_tdb = NULL;
+ struct tdb_context *dst_tdb = NULL;
+ char *tmp_path = NULL;
+ struct stat st;
+ int count1, count2;
+ int saved_errno = 0;
+ int ret = -1;
+
+ if (stat(src_path, &st) != 0) {
+ DEBUG(3, ("Could not stat '%s': %s\n", src_path,
+ strerror(errno)));
+ goto done;
+ }
+
+ /* open old tdb RDWR - so we can lock it */
+ src_tdb = tdb_open_log(src_path, 0, TDB_DEFAULT, O_RDWR, 0);
+ if (src_tdb == NULL) {
+ DEBUG(3, ("Failed to open tdb '%s'\n", src_path));
+ goto done;
+ }
+
+ if (tdb_lockall(src_tdb) != 0) {
+ DEBUG(3, ("Failed to lock tdb '%s'\n", src_path));
+ goto done;
+ }
+
+ tmp_path = talloc_asprintf(ctx, "%s%s", dst_path, ".tmp");
+ unlink(tmp_path);
+ dst_tdb = tdb_open_log(tmp_path,
+ hash_size ? hash_size : tdb_hash_size(src_tdb),
+ TDB_DEFAULT, O_RDWR | O_CREAT | O_EXCL,
+ st.st_mode & 0777);
+ if (dst_tdb == NULL) {
+ DEBUG(3, ("Error creating tdb '%s': %s\n", tmp_path,
+ strerror(errno)));
+ saved_errno = errno;
+ unlink(tmp_path);
+ goto done;
+ }
+
+ count1 = tdb_copy(src_tdb, dst_tdb);
+ if (count1 < 0) {
+ DEBUG(3, ("Failed to copy tdb '%s': %s\n", src_path,
+ strerror(errno)));
+ tdb_close(dst_tdb);
+ goto done;
+ }
+
+ /* reopen ro and do basic verification */
+ tdb_close(dst_tdb);
+ dst_tdb = tdb_open_log(tmp_path, 0, TDB_DEFAULT, O_RDONLY, 0);
+ if (!dst_tdb) {
+ DEBUG(3, ("Failed to reopen tdb '%s': %s\n", tmp_path,
+ strerror(errno)));
+ goto done;
+ }
+ count2 = tdb_verify_basic(dst_tdb);
+ if (count2 != count1) {
+ DEBUG(3, ("Failed to verify result of copying tdb '%s'.\n",
+ src_path));
+ tdb_close(dst_tdb);
+ goto done;
+ }
+
+ DEBUG(10, ("tdb_backup: successfully copied %d entries\n", count1));
+
+ /* make sure the new tdb has reached stable storage
+ * then rename it to its destination */
+ fsync(tdb_fd(dst_tdb));
+ tdb_close(dst_tdb);
+ unlink(dst_path);
+ if (rename(tmp_path, dst_path) != 0) {
+ DEBUG(3, ("Failed to rename '%s' to '%s': %s\n",
+ tmp_path, dst_path, strerror(errno)));
+ goto done;
+ }
+
+ /* success */
+ ret = 0;
+
+done:
+ if (src_tdb != NULL) {
+ tdb_close(src_tdb);
+ }
+ if (tmp_path != NULL) {
+ unlink(tmp_path);
+ TALLOC_FREE(tmp_path);
+ }
+ if (saved_errno != 0) {
+ errno = saved_errno;
+ }
+ return ret;
+}
+
+static int rename_file_with_suffix(TALLOC_CTX *ctx, const char *path,
+ const char *suffix)
+{
+ int ret = -1;
+ char *dst_path;
+
+ dst_path = talloc_asprintf(ctx, "%s%s", path, suffix);
+
+ ret = (rename(path, dst_path) != 0);
+
+ if (ret == 0) {
+ DEBUG(5, ("moved '%s' to '%s'\n", path, dst_path));
+ } else if (errno == ENOENT) {
+ DEBUG(3, ("file '%s' does not exist - so not moved\n", path));
+ ret = 0;
+ } else {
+ DEBUG(3, ("error renaming %s to %s: %s\n", path, dst_path,
+ strerror(errno)));
+ }
+
+ TALLOC_FREE(dst_path);
+ return ret;
+}
+
+/*
+ * do a backup of a tdb, moving the destination out of the way first
+ */
+static int tdb_backup_with_rotate(TALLOC_CTX *ctx, const char *src_path,
+ const char *dst_path, int hash_size,
+ const char *rotate_suffix,
+ bool retry_norotate_if_nospc,
+ bool rename_as_last_resort_if_nospc)
+{
+ int ret;
+
+ rename_file_with_suffix(ctx, dst_path, rotate_suffix);
+
+ ret = tdb_backup(ctx, src_path, dst_path, hash_size);
+
+ if (ret != 0) {
+ DEBUG(10, ("backup of %s failed: %s\n", src_path, strerror(errno)));
+ }
+ if ((ret != 0) && (errno == ENOSPC) && retry_norotate_if_nospc)
+ {
+ char *rotate_path = talloc_asprintf(ctx, "%s%s", dst_path,
+ rotate_suffix);
+ DEBUG(10, ("backup of %s failed due to lack of space\n",
+ src_path));
+ DEBUGADD(10, ("trying to free some space by removing rotated "
+ "dst %s\n", rotate_path));
+ if (unlink(rotate_path) == -1) {
+ DEBUG(10, ("unlink of %s failed: %s\n", rotate_path,
+ strerror(errno)));
+ } else {
+ ret = tdb_backup(ctx, src_path, dst_path, hash_size);
+ }
+ TALLOC_FREE(rotate_path);
+ }
+
+ if ((ret != 0) && (errno == ENOSPC) && rename_as_last_resort_if_nospc)
+ {
+ DEBUG(10, ("backup of %s failed due to lack of space\n",
+ src_path));
+ DEBUGADD(10, ("using 'rename' as a last resort\n"));
+ ret = rename(src_path, dst_path);
+ }
+
+ return ret;
+}
+
+/*
+ * validation function with backup handling:
+ *
+ * - calls tdb_validate
+ * - if the tdb is ok, create a backup "name.bak", possibly moving
+ * existing backup to name.bak.old,
+ * return 0 (success) even if the backup fails
+ * - if the tdb is corrupt:
+ * - move the tdb to "name.corrupt"
+ * - check if there is valid backup.
+ * if so, restore the backup.
+ * if restore is successful, return 0 (success),
+ * - otherwise return -1 (failure)
+ */
+int tdb_validate_and_backup(const char *tdb_path,
+ tdb_validate_data_func validate_fn)
+{
+ int ret = -1;
+ const char *backup_suffix = ".bak";
+ const char *corrupt_suffix = ".corrupt";
+ const char *rotate_suffix = ".old";
+ char *tdb_path_backup;
+ struct stat st;
+ TALLOC_CTX *ctx = NULL;
+
+ ctx = talloc_new(NULL);
+ if (ctx == NULL) {
+ DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
+ goto done;
+ }
+
+ tdb_path_backup = talloc_asprintf(ctx, "%s%s", tdb_path, backup_suffix);
+
+ ret = tdb_validate_open(tdb_path, validate_fn);
+
+ if (ret == 0) {
+ DEBUG(1, ("tdb '%s' is valid\n", tdb_path));
+ ret = tdb_backup_with_rotate(ctx, tdb_path, tdb_path_backup, 0,
+ rotate_suffix, True, False);
+ if (ret != 0) {
+ DEBUG(1, ("Error creating backup of tdb '%s'\n",
+ tdb_path));
+ /* the actual validation was successful: */
+ ret = 0;
+ } else {
+ DEBUG(1, ("Created backup '%s' of tdb '%s'\n",
+ tdb_path_backup, tdb_path));
+ }
+ } else {
+ DEBUG(1, ("tdb '%s' is invalid\n", tdb_path));
+
+ ret =stat(tdb_path_backup, &st);
+ if (ret != 0) {
+ DEBUG(5, ("Could not stat '%s': %s\n", tdb_path_backup,
+ strerror(errno)));
+ DEBUG(1, ("No backup found.\n"));
+ } else {
+ DEBUG(1, ("backup '%s' found.\n", tdb_path_backup));
+ ret = tdb_validate_open(tdb_path_backup, validate_fn);
+ if (ret != 0) {
+ DEBUG(1, ("Backup '%s' is invalid.\n",
+ tdb_path_backup));
+ }
+ }
+
+ if (ret != 0) {
+ int renamed = rename_file_with_suffix(ctx, tdb_path,
+ corrupt_suffix);
+ if (renamed != 0) {
+ DEBUG(1, ("Error moving tdb to '%s%s'\n",
+ tdb_path, corrupt_suffix));
+ } else {
+ DEBUG(1, ("Corrupt tdb stored as '%s%s'\n",
+ tdb_path, corrupt_suffix));
+ }
+ goto done;
+ }
+
+ DEBUG(1, ("valid backup '%s' found\n", tdb_path_backup));
+ ret = tdb_backup_with_rotate(ctx, tdb_path_backup, tdb_path, 0,
+ corrupt_suffix, True, True);
+ if (ret != 0) {
+ DEBUG(1, ("Error restoring backup from '%s'\n",
+ tdb_path_backup));
+ } else {
+ DEBUG(1, ("Restored tdb backup from '%s'\n",
+ tdb_path_backup));
+ }
+ }
+
+done:
+ TALLOC_FREE(ctx);
+ return ret;
+}
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