src/lib-sql/driver-sqlite.c

/* Copyright (c) 2006-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "array.h"
#include "str.h"
#include "hex-binary.h"
#include "sql-api-private.h"

#ifdef BUILD_SQLITE
#include <sqlite3.h>

/* retry time if db is busy (in ms) */
static const int sqlite_busy_timeout = 1000;

struct sqlite_db {
    struct sql_db api;

    pool_t pool;
    const char *dbfile;
    sqlite3 *sqlite;
    bool connected:1;
    int rc;
};

struct sqlite_result {
    struct sql_result api;
    sqlite3_stmt *stmt;
    unsigned int cols;
    const char **row;
};

struct sqlite_transaction_context {
    struct sql_transaction_context ctx;
    bool failed:1;
};

extern const struct sql_db driver_sqlite_db;
extern const struct sql_result driver_sqlite_result;
extern const struct sql_result driver_sqlite_error_result;

static int driver_sqlite_connect(struct sql_db *_db)
{
    struct sqlite_db *db = (struct sqlite_db *)_db;

    if (db->connected)
        return 1;

    db->rc = sqlite3_open(db->dbfile, &db->sqlite);

    if (db->rc == SQLITE_OK) {
        db->connected = TRUE;
        sqlite3_busy_timeout(db->sqlite, sqlite_busy_timeout);
        return 1;
    } else {
        i_error("sqlite: open(%s) failed: %s", db->dbfile,
            sqlite3_errmsg(db->sqlite));
        sqlite3_close(db->sqlite);
        db->sqlite = NULL;
        return -1;
    }
}

static void driver_sqlite_disconnect(struct sql_db *_db)
{
    struct sqlite_db *db = (struct sqlite_db *)_db;

    sqlite3_close(db->sqlite);
    db->sqlite = NULL;
}

static struct sql_db *driver_sqlite_init_v(const char *connect_string)
{
    struct sqlite_db *db;
    pool_t pool;

    i_assert(connect_string != NULL);

    pool = pool_alloconly_create("sqlite driver", 512);
    db = p_new(pool, struct sqlite_db, 1);
    db->pool = pool;
    db->api = driver_sqlite_db;
    db->dbfile = p_strdup(db->pool, connect_string);
    db->connected = FALSE;

    return &db->api;
}

static void driver_sqlite_deinit_v(struct sql_db *_db)
{
    struct sqlite_db *db = (struct sqlite_db *)_db;

    _db->no_reconnect = TRUE;
    sql_db_set_state(&db->api, SQL_DB_STATE_DISCONNECTED);

    sqlite3_close(db->sqlite);
    array_free(&_db->module_contexts);
    pool_unref(&db->pool);
}

static const char *
driver_sqlite_escape_string(struct sql_db *_db ATTR_UNUSED,
                const char *string)
{
    const char *p;
    char *dest, *destbegin;

    /* find the first ' */
    for (p = string; *p != '\''; p++) {
        if (*p == '\0')
            return t_strdup_noconst(string);
    }

    /* @UNSAFE: escape ' with '' */
    dest = destbegin = t_buffer_get((p - string) + strlen(string) * 2 + 1);

    memcpy(dest, string, p - string);
    dest += p - string;

    for (; *p != '\0'; p++) {
        *dest++ = *p;
        if (*p == '\'')
            *dest++ = *p;
    }
    *dest++ = '\0';
    t_buffer_alloc(dest - destbegin);

    return destbegin;
}

static void driver_sqlite_exec(struct sql_db *_db, const char *query)
{
    struct sqlite_db *db = (struct sqlite_db *)_db;

    if (driver_sqlite_connect(_db) < 0)
        return;

    db->rc = sqlite3_exec(db->sqlite, query, NULL, NULL, NULL);
    if (db->rc != SQLITE_OK) {
        i_error("sqlite: exec(%s) failed: %s (%d)",
            query, sqlite3_errmsg(db->sqlite), db->rc);
    }
}

static void driver_sqlite_query(struct sql_db *db, const char *query,
                sql_query_callback_t *callback, void *context)
{
    struct sql_result *result;

    result = sql_query_s(db, query);
    result->callback = TRUE;
    callback(result, context);
    result->callback = FALSE;
    sql_result_unref(result);
}

static struct sql_result *
driver_sqlite_query_s(struct sql_db *_db, const char *query)
{
    struct sqlite_db *db = (struct sqlite_db *)_db;
    struct sqlite_result *result;
    int rc;

    result = i_new(struct sqlite_result, 1);

    if (driver_sqlite_connect(_db) < 0) {
        result->api = driver_sqlite_error_result;
        result->stmt = NULL;
        result->cols = 0;
    } else {
        rc = sqlite3_prepare(db->sqlite, query, -1, &result->stmt, NULL);
        if (rc == SQLITE_OK) {
            result->api = driver_sqlite_result;
            result->cols = sqlite3_column_count(result->stmt);
            result->row = i_new(const char *, result->cols);
        } else {
            result->api = driver_sqlite_error_result;
            result->stmt = NULL;
            result->cols = 0;
        }
    }
    result->api.db = _db;
    result->api.refcount = 1;

    return &result->api;
}

static void driver_sqlite_result_free(struct sql_result *_result)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;
    struct sqlite_db *db = (struct sqlite_db *) result->api.db;
    int rc;

    if (_result->callback)
        return;

    if (result->stmt != NULL) {
        if ((rc = sqlite3_finalize(result->stmt)) != SQLITE_OK) {
            i_warning("sqlite: finalize failed: %s (%d)",
                  sqlite3_errmsg(db->sqlite), rc);
        }
        i_free(result->row);
    }
    i_free(result);
}

static int driver_sqlite_result_next_row(struct sql_result *_result)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;

    switch (sqlite3_step(result->stmt)) {
    case SQLITE_ROW:
        return 1;
    case SQLITE_DONE:
        return 0;
    default:
        return -1;
    }
}

static unsigned int
driver_sqlite_result_get_fields_count(struct sql_result *_result)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;

    return result->cols;
}

static const char *
driver_sqlite_result_get_field_name(struct sql_result *_result,
                    unsigned int idx)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;

    return sqlite3_column_name(result->stmt, idx);
}

static int driver_sqlite_result_find_field(struct sql_result *_result,
                       const char *field_name)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;
    unsigned int i;

    for (i = 0; i < result->cols; ++i) {
        const char *col = sqlite3_column_name(result->stmt, i);

        if (strcmp(col, field_name) == 0)
            return i;
    }

    return -1;
}

static const char *
driver_sqlite_result_get_field_value(struct sql_result *_result,
                     unsigned int idx)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;

    return (const char*)sqlite3_column_text(result->stmt, idx);
}

static const unsigned char *
driver_sqlite_result_get_field_value_binary(struct sql_result *_result,
                        unsigned int idx, size_t *size_r)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;

    *size_r = sqlite3_column_bytes(result->stmt, idx);
    return sqlite3_column_blob(result->stmt, idx);
}

static const char *
driver_sqlite_result_find_field_value(struct sql_result *result,
                     const char *field_name)
{
    int idx;

    idx = driver_sqlite_result_find_field(result, field_name);
    if (idx < 0)
        return NULL;
    return driver_sqlite_result_get_field_value(result, idx);
}

static const char *const *
driver_sqlite_result_get_values(struct sql_result *_result)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;
    unsigned int i;

    for (i = 0; i < result->cols; ++i) {
        result->row[i] =
            driver_sqlite_result_get_field_value(_result, i);
    }

    return (const char *const *)result->row;
}

static const char *driver_sqlite_result_get_error(struct sql_result *_result)
{
    struct sqlite_result *result = (struct sqlite_result *)_result;
    struct sqlite_db *db = (struct sqlite_db *)result->api.db;

    return sqlite3_errmsg(db->sqlite);
}

static struct sql_transaction_context *
driver_sqlite_transaction_begin(struct sql_db *_db)
{
    struct sqlite_transaction_context *ctx;
    struct sqlite_db *db = (struct sqlite_db *)_db;

    ctx = i_new(struct sqlite_transaction_context, 1);
    ctx->ctx.db = _db;

    sql_exec(_db, "BEGIN TRANSACTION");
    if (db->rc != SQLITE_OK)
        ctx->failed = TRUE;

    return &ctx->ctx;
}

static void
driver_sqlite_transaction_rollback(struct sql_transaction_context *_ctx)
{
    struct sqlite_transaction_context *ctx =
        (struct sqlite_transaction_context *)_ctx;

    sql_exec(_ctx->db, "ROLLBACK");
    i_free(ctx);
}

static void
driver_sqlite_transaction_commit(struct sql_transaction_context *_ctx,
                 sql_commit_callback_t *callback, void *context)
{
    struct sqlite_transaction_context *ctx =
        (struct sqlite_transaction_context *)_ctx;
    struct sqlite_db *db = (struct sqlite_db *)ctx->ctx.db;
    struct sql_commit_result commit_result;

    if (!ctx->failed) {
        sql_exec(_ctx->db, "COMMIT");
        if (db->rc != SQLITE_OK)
            ctx->failed = TRUE;
    }

    i_zero(&commit_result);
    if (ctx->failed) {
        commit_result.error = sqlite3_errmsg(db->sqlite);
        callback(&commit_result, context);
                /* also does i_free(ctx) */
        driver_sqlite_transaction_rollback(_ctx);
    } else {
        callback(&commit_result, context);
        i_free(ctx);
    }
}

static int
driver_sqlite_transaction_commit_s(struct sql_transaction_context *_ctx,
                   const char **error_r)
{
    struct sqlite_transaction_context *ctx =
        (struct sqlite_transaction_context *)_ctx;
    struct sqlite_db *db = (struct sqlite_db *) ctx->ctx.db;

    if (ctx->failed) {
                /* also does i_free(ctx) */
        driver_sqlite_transaction_rollback(_ctx);
        return -1;
    }

    sql_exec(_ctx->db, "COMMIT");
    *error_r = sqlite3_errmsg(db->sqlite);
    i_free(ctx);
    return 0;
}

static void
driver_sqlite_update(struct sql_transaction_context *_ctx, const char *query,
             unsigned int *affected_rows)
{
    struct sqlite_transaction_context *ctx =
        (struct sqlite_transaction_context *)_ctx;
    struct sqlite_db *db = (struct sqlite_db *)ctx->ctx.db;

    if (ctx->failed)
        return;

    sql_exec(_ctx->db, query);
    if (db->rc != SQLITE_OK)
        ctx->failed = TRUE;
    else if (affected_rows != NULL)
        *affected_rows = sqlite3_changes(db->sqlite);
}

static const char *
driver_sqlite_escape_blob(struct sql_db *_db ATTR_UNUSED,
              const unsigned char *data, size_t size)
{
    string_t *str = t_str_new(128);

    str_append(str, "x'");
    binary_to_hex_append(str, data, size);
    str_append_c(str, '\'');
    return str_c(str);
}

const struct sql_db driver_sqlite_db = {
    .name = "sqlite",
    .flags = SQL_DB_FLAG_BLOCKING,

    .v = {
        .init = driver_sqlite_init_v,
        .deinit = driver_sqlite_deinit_v,
        .connect = driver_sqlite_connect,
        .disconnect = driver_sqlite_disconnect,
        .escape_string = driver_sqlite_escape_string,
        .exec = driver_sqlite_exec,
        .query = driver_sqlite_query,
        .query_s = driver_sqlite_query_s,

        .transaction_begin = driver_sqlite_transaction_begin,
        .transaction_commit = driver_sqlite_transaction_commit,
        .transaction_commit_s = driver_sqlite_transaction_commit_s,
        .transaction_rollback = driver_sqlite_transaction_rollback,

        .update = driver_sqlite_update,

        .escape_blob = driver_sqlite_escape_blob,
    }
};

const struct sql_result driver_sqlite_result = {
    .v = {
        .free = driver_sqlite_result_free,
        .next_row = driver_sqlite_result_next_row,
        .get_fields_count = driver_sqlite_result_get_fields_count,
        .get_field_name = driver_sqlite_result_get_field_name,
        .find_field = driver_sqlite_result_find_field,
        .get_field_value = driver_sqlite_result_get_field_value,
        .get_field_value_binary = driver_sqlite_result_get_field_value_binary,
        .find_field_value = driver_sqlite_result_find_field_value,
        .get_values = driver_sqlite_result_get_values,
        .get_error = driver_sqlite_result_get_error,
    }
};

static int
driver_sqlite_result_error_next_row(struct sql_result *result ATTR_UNUSED)
{
    return -1;
}

const struct sql_result driver_sqlite_error_result = {
    .v = {
        .free = driver_sqlite_result_free,
        .next_row = driver_sqlite_result_error_next_row,
        .get_error = driver_sqlite_result_get_error,
    }
};

const char *driver_sqlite_version = DOVECOT_ABI_VERSION;

void driver_sqlite_init(void);
void driver_sqlite_deinit(void);

void driver_sqlite_init(void)
{
    sql_driver_register(&driver_sqlite_db);
}

void driver_sqlite_deinit(void)
{
    sql_driver_unregister(&driver_sqlite_db);
}

#endif