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Diffstat (limited to '')
| -rw-r--r-- | utils/nfsdcltrack/sqlite.c | 604 |
1 files changed, 604 insertions, 0 deletions
diff --git a/utils/nfsdcltrack/sqlite.c b/utils/nfsdcltrack/sqlite.c new file mode 100644 index 0000000..cf0c6a4 --- /dev/null +++ b/utils/nfsdcltrack/sqlite.c @@ -0,0 +1,604 @@ +/* + * Copyright (C) 2011 Red Hat, Jeff Layton <jlayton@redhat.com> + * + * 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 2 + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301, USA. + */ + +/* + * Explanation: + * + * This file contains the code to manage the sqlite backend database for the + * nfsdcltrack usermodehelper upcall program. + * + * The main database is called main.sqlite and contains the following tables: + * + * parameters: simple key/value pairs for storing database info + * + * clients: an "id" column containing a BLOB with the long-form clientid as + * sent by the client, a "time" column containing a timestamp (in + * epoch seconds) of when the record was last updated, and a + * "has_session" column containing a boolean value indicating + * whether the client has sessions (v4.1+) or not (v4.0). + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif /* HAVE_CONFIG_H */ + +#include <dirent.h> +#include <errno.h> +#include <stdio.h> +#include <stdbool.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <fcntl.h> +#include <inttypes.h> +#include <unistd.h> +#include <sqlite3.h> +#include <linux/limits.h> + +#include "xlog.h" +#include "sqlite.h" + +#define CLTRACK_SQLITE_LATEST_SCHEMA_VERSION 2 + +/* in milliseconds */ +#define CLTRACK_SQLITE_BUSY_TIMEOUT 10000 + +/* private data structures */ + +/* global variables */ + +/* reusable pathname and sql command buffer */ +static char buf[PATH_MAX]; + +/* global database handle */ +static sqlite3 *dbh; + +/* forward declarations */ + +/* make a directory, ignoring EEXIST errors unless it's not a directory */ +static int +mkdir_if_not_exist(const char *dirname) +{ + int ret; + struct stat statbuf; + + ret = mkdir(dirname, S_IRWXU); + if (ret && errno != EEXIST) + return -errno; + + ret = stat(dirname, &statbuf); + if (ret) + return -errno; + + if (!S_ISDIR(statbuf.st_mode)) + ret = -ENOTDIR; + + return ret; +} + +static int +sqlite_query_schema_version(void) +{ + int ret; + sqlite3_stmt *stmt = NULL; + + /* prepare select query */ + ret = sqlite3_prepare_v2(dbh, + "SELECT value FROM parameters WHERE key == \"version\";", + -1, &stmt, NULL); + if (ret != SQLITE_OK) { + xlog(D_GENERAL, "Unable to prepare select statement: %s", + sqlite3_errmsg(dbh)); + ret = 0; + goto out; + } + + /* query schema version */ + ret = sqlite3_step(stmt); + if (ret != SQLITE_ROW) { + xlog(D_GENERAL, "Select statement execution failed: %s", + sqlite3_errmsg(dbh)); + ret = 0; + goto out; + } + + ret = sqlite3_column_int(stmt, 0); +out: + sqlite3_finalize(stmt); + return ret; +} + +static int +sqlite_maindb_update_v1_to_v2(void) +{ + int ret, ret2; + char *err; + + /* begin transaction */ + ret = sqlite3_exec(dbh, "BEGIN EXCLUSIVE TRANSACTION;", NULL, NULL, + &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to begin transaction: %s", err); + goto rollback; + } + + /* + * Check schema version again. This time, under an exclusive + * transaction to guard against racing DB setup attempts + */ + ret = sqlite_query_schema_version(); + switch (ret) { + case 1: + /* Still at v1 -- do conversion */ + break; + case CLTRACK_SQLITE_LATEST_SCHEMA_VERSION: + /* Someone else raced in and set it up */ + ret = 0; + goto rollback; + default: + /* Something went wrong -- fail! */ + ret = -EINVAL; + goto rollback; + } + + /* create v2 clients table */ + ret = sqlite3_exec(dbh, "ALTER TABLE clients ADD COLUMN " + "has_session INTEGER;", + NULL, NULL, &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to update clients table: %s", err); + goto rollback; + } + + ret = snprintf(buf, sizeof(buf), "UPDATE parameters SET value = %d " + "WHERE key = \"version\";", + CLTRACK_SQLITE_LATEST_SCHEMA_VERSION); + if (ret < 0) { + xlog(L_ERROR, "sprintf failed!"); + goto rollback; + } else if ((size_t)ret >= sizeof(buf)) { + xlog(L_ERROR, "sprintf output too long! (%d chars)", ret); + ret = -EINVAL; + goto rollback; + } + + ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to update schema version: %s", err); + goto rollback; + } + + ret = sqlite3_exec(dbh, "COMMIT TRANSACTION;", NULL, NULL, &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to commit transaction: %s", err); + goto rollback; + } +out: + sqlite3_free(err); + return ret; +rollback: + ret2 = sqlite3_exec(dbh, "ROLLBACK TRANSACTION;", NULL, NULL, &err); + if (ret2 != SQLITE_OK) + xlog(L_ERROR, "Unable to rollback transaction: %s", err); + goto out; +} + +/* + * Start an exclusive transaction and recheck the DB schema version. If it's + * still zero (indicating a new database) then set it up. If that all works, + * then insert schema version into the parameters table and commit the + * transaction. On any error, rollback the transaction. + */ +static int +sqlite_maindb_init_v2(void) +{ + int ret, ret2; + char *err = NULL; + + /* Start a transaction */ + ret = sqlite3_exec(dbh, "BEGIN EXCLUSIVE TRANSACTION;", NULL, NULL, + &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to begin transaction: %s", err); + if (err) + sqlite3_free(err); + return ret; + } + + /* + * Check schema version again. This time, under an exclusive + * transaction to guard against racing DB setup attempts + */ + ret = sqlite_query_schema_version(); + switch (ret) { + case 0: + /* Query failed again -- set up DB */ + break; + case CLTRACK_SQLITE_LATEST_SCHEMA_VERSION: + /* Someone else raced in and set it up */ + ret = 0; + goto rollback; + default: + /* Something went wrong -- fail! */ + ret = -EINVAL; + goto rollback; + } + + ret = sqlite3_exec(dbh, "CREATE TABLE parameters " + "(key TEXT PRIMARY KEY, value TEXT);", + NULL, NULL, &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to create parameter table: %s", err); + goto rollback; + } + + /* create the "clients" table */ + ret = sqlite3_exec(dbh, "CREATE TABLE clients (id BLOB PRIMARY KEY, " + "time INTEGER, has_session INTEGER);", + NULL, NULL, &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to create clients table: %s", err); + goto rollback; + } + + + /* insert version into parameters table */ + ret = snprintf(buf, sizeof(buf), "INSERT OR FAIL INTO parameters " + "values (\"version\", \"%d\");", + CLTRACK_SQLITE_LATEST_SCHEMA_VERSION); + if (ret < 0) { + xlog(L_ERROR, "sprintf failed!"); + goto rollback; + } else if ((size_t)ret >= sizeof(buf)) { + xlog(L_ERROR, "sprintf output too long! (%d chars)", ret); + ret = -EINVAL; + goto rollback; + } + + ret = sqlite3_exec(dbh, (const char *)buf, NULL, NULL, &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to insert into parameter table: %s", err); + goto rollback; + } + + ret = sqlite3_exec(dbh, "COMMIT TRANSACTION;", NULL, NULL, &err); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to commit transaction: %s", err); + goto rollback; + } +out: + sqlite3_free(err); + return ret; + +rollback: + /* Attempt to rollback the transaction */ + ret2 = sqlite3_exec(dbh, "ROLLBACK TRANSACTION;", NULL, NULL, &err); + if (ret2 != SQLITE_OK) + xlog(L_ERROR, "Unable to rollback transaction: %s", err); + goto out; +} + +/* Open the database and set up the database handle for it */ +int +sqlite_prepare_dbh(const char *topdir) +{ + int ret; + + /* Do nothing if the database handle is already set up */ + if (dbh) + return 0; + + ret = snprintf(buf, PATH_MAX - 1, "%s/main.sqlite", topdir); + if (ret < 0) + return ret; + + buf[PATH_MAX - 1] = '\0'; + + /* open a new DB handle */ + ret = sqlite3_open(buf, &dbh); + if (ret != SQLITE_OK) { + /* try to create the dir */ + ret = mkdir_if_not_exist(topdir); + if (ret) + goto out_close; + + /* retry open */ + ret = sqlite3_open(buf, &dbh); + if (ret != SQLITE_OK) + goto out_close; + } + + /* set busy timeout */ + ret = sqlite3_busy_timeout(dbh, CLTRACK_SQLITE_BUSY_TIMEOUT); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "Unable to set sqlite busy timeout: %s", + sqlite3_errmsg(dbh)); + goto out_close; + } + + ret = sqlite_query_schema_version(); + switch (ret) { + case CLTRACK_SQLITE_LATEST_SCHEMA_VERSION: + /* DB is already set up. Do nothing */ + ret = 0; + break; + case 1: + /* Old DB -- update to new schema */ + ret = sqlite_maindb_update_v1_to_v2(); + if (ret) + goto out_close; + break; + case 0: + /* Query failed -- try to set up new DB */ + ret = sqlite_maindb_init_v2(); + if (ret) + goto out_close; + break; + default: + /* Unknown DB version -- downgrade? Fail */ + xlog(L_ERROR, "Unsupported database schema version! " + "Expected %d, got %d.", + CLTRACK_SQLITE_LATEST_SCHEMA_VERSION, ret); + ret = -EINVAL; + goto out_close; + } + + return ret; +out_close: + sqlite3_close(dbh); + dbh = NULL; + return ret; +} + +/* + * Create a client record + * + * Returns a non-zero sqlite error code, or SQLITE_OK (aka 0) + */ +int +sqlite_insert_client(const unsigned char *clname, const size_t namelen, + const bool has_session, const bool zerotime) +{ + int ret; + sqlite3_stmt *stmt = NULL; + + if (zerotime) + ret = sqlite3_prepare_v2(dbh, "INSERT OR REPLACE INTO clients " + "VALUES (?, 0, ?);", -1, &stmt, NULL); + else + ret = sqlite3_prepare_v2(dbh, "INSERT OR REPLACE INTO clients " + "VALUES (?, strftime('%s', 'now'), ?);", -1, + &stmt, NULL); + + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: insert statement prepare failed: %s", + __func__, sqlite3_errmsg(dbh)); + return ret; + } + + ret = sqlite3_bind_blob(stmt, 1, (const void *)clname, namelen, + SQLITE_STATIC); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: bind blob failed: %s", __func__, + sqlite3_errmsg(dbh)); + goto out_err; + } + + ret = sqlite3_bind_int(stmt, 2, (int)has_session); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: bind int failed: %s", __func__, + sqlite3_errmsg(dbh)); + goto out_err; + } + + ret = sqlite3_step(stmt); + if (ret == SQLITE_DONE) + ret = SQLITE_OK; + else + xlog(L_ERROR, "%s: unexpected return code from insert: %s", + __func__, sqlite3_errmsg(dbh)); + +out_err: + xlog(D_GENERAL, "%s: returning %d", __func__, ret); + sqlite3_finalize(stmt); + return ret; +} + +/* Remove a client record */ +int +sqlite_remove_client(const unsigned char *clname, const size_t namelen) +{ + int ret; + sqlite3_stmt *stmt = NULL; + + ret = sqlite3_prepare_v2(dbh, "DELETE FROM clients WHERE id==?", -1, + &stmt, NULL); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: statement prepare failed: %s", + __func__, sqlite3_errmsg(dbh)); + goto out_err; + } + + ret = sqlite3_bind_blob(stmt, 1, (const void *)clname, namelen, + SQLITE_STATIC); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: bind blob failed: %s", __func__, + sqlite3_errmsg(dbh)); + goto out_err; + } + + ret = sqlite3_step(stmt); + if (ret == SQLITE_DONE) + ret = SQLITE_OK; + else + xlog(L_ERROR, "%s: unexpected return code from delete: %d", + __func__, ret); + +out_err: + xlog(D_GENERAL, "%s: returning %d", __func__, ret); + sqlite3_finalize(stmt); + return ret; +} + +/* + * Is the given clname in the clients table? If so, then update its timestamp + * and return success. If the record isn't present, or the update fails, then + * return an error. + */ +int +sqlite_check_client(const unsigned char *clname, const size_t namelen, + const bool has_session) +{ + int ret; + sqlite3_stmt *stmt = NULL; + + ret = sqlite3_prepare_v2(dbh, "SELECT count(*) FROM clients WHERE " + "id==?", -1, &stmt, NULL); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: unable to prepare update statement: %s", + __func__, sqlite3_errmsg(dbh)); + goto out_err; + } + + ret = sqlite3_bind_blob(stmt, 1, (const void *)clname, namelen, + SQLITE_STATIC); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: bind blob failed: %s", + __func__, sqlite3_errmsg(dbh)); + goto out_err; + } + + ret = sqlite3_step(stmt); + if (ret != SQLITE_ROW) { + xlog(L_ERROR, "%s: unexpected return code from select: %d", + __func__, ret); + goto out_err; + } + + ret = sqlite3_column_int(stmt, 0); + xlog(D_GENERAL, "%s: select returned %d rows", __func__, ret); + if (ret != 1) { + ret = -EACCES; + goto out_err; + } + + /* Only update timestamp for v4.0 clients */ + if (has_session) { + ret = SQLITE_OK; + goto out_err; + } + + sqlite3_finalize(stmt); + stmt = NULL; + ret = sqlite3_prepare_v2(dbh, "UPDATE OR FAIL clients SET " + "time=strftime('%s', 'now') WHERE id==?", + -1, &stmt, NULL); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: unable to prepare update statement: %s", + __func__, sqlite3_errmsg(dbh)); + goto out_err; + } + + ret = sqlite3_bind_blob(stmt, 1, (const void *)clname, namelen, + SQLITE_STATIC); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: bind blob failed: %s", + __func__, sqlite3_errmsg(dbh)); + goto out_err; + } + + ret = sqlite3_step(stmt); + if (ret == SQLITE_DONE) + ret = SQLITE_OK; + else + xlog(L_ERROR, "%s: unexpected return code from update: %s", + __func__, sqlite3_errmsg(dbh)); + +out_err: + xlog(D_GENERAL, "%s: returning %d", __func__, ret); + sqlite3_finalize(stmt); + return ret; +} + +/* + * remove any client records that were not reclaimed since grace_start. + */ +int +sqlite_remove_unreclaimed(uint64_t grace_start) +{ + int ret; + char *err = NULL; + + ret = snprintf(buf, sizeof(buf), "DELETE FROM clients WHERE time < %"PRIu64, + grace_start); + if (ret < 0) { + return ret; + } else if ((size_t)ret >= sizeof(buf)) { + ret = -EINVAL; + return ret; + } + + ret = sqlite3_exec(dbh, buf, NULL, NULL, &err); + if (ret != SQLITE_OK) + xlog(L_ERROR, "%s: delete failed: %s", __func__, err); + + xlog(D_GENERAL, "%s: returning %d", __func__, ret); + sqlite3_free(err); + return ret; +} + +/* + * Are there any clients that are possibly still reclaiming? Return a positive + * integer (usually number of clients) if so. If not, then return 0. On any + * error, return non-zero. + */ +int +sqlite_query_reclaiming(const time_t grace_start) +{ + int ret; + sqlite3_stmt *stmt = NULL; + + ret = sqlite3_prepare_v2(dbh, "SELECT count(*) FROM clients WHERE " + "time < ? OR has_session != 1", -1, &stmt, NULL); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: unable to prepare select statement: %s", + __func__, sqlite3_errmsg(dbh)); + return ret; + } + + ret = sqlite3_bind_int64(stmt, 1, (sqlite3_int64)grace_start); + if (ret != SQLITE_OK) { + xlog(L_ERROR, "%s: bind int64 failed: %s", + __func__, sqlite3_errmsg(dbh)); + return ret; + } + + ret = sqlite3_step(stmt); + if (ret != SQLITE_ROW) { + xlog(L_ERROR, "%s: unexpected return code from select: %s", + __func__, sqlite3_errmsg(dbh)); + return ret; + } + + ret = sqlite3_column_int(stmt, 0); + sqlite3_finalize(stmt); + xlog(D_GENERAL, "%s: there are %d clients that have not completed " + "reclaim", __func__, ret); + return ret; +} |