src/auth/userdb-sql.c

/* Copyright (c) 2004-2018 Dovecot authors, see the included COPYING file */

#include "auth-common.h"
#include "userdb.h"

#ifdef USERDB_SQL

#include "auth-cache.h"
#include "db-sql.h"

#include <string.h>

struct sql_userdb_module {
    struct userdb_module module;

    struct sql_connection *conn;
};

struct userdb_sql_request {
    struct auth_request *auth_request;
    userdb_callback_t *callback;
};

struct sql_userdb_iterate_context {
    struct userdb_iterate_context ctx;
    struct sql_result *result;
    bool freed:1;
    bool call_iter:1;
};

static void userdb_sql_iterate_next(struct userdb_iterate_context *_ctx);
static int userdb_sql_iterate_deinit(struct userdb_iterate_context *_ctx);

static void
sql_query_get_result(struct sql_result *result,
             struct auth_request *auth_request)
{
    const char *name, *value;
    unsigned int i, fields_count;

    fields_count = sql_result_get_fields_count(result);
    for (i = 0; i < fields_count; i++) {
        name = sql_result_get_field_name(result, i);
        value = sql_result_get_field_value(result, i);

        if (*name != '\0' && value != NULL) {
            auth_request_set_userdb_field(auth_request,
                              name, value);
        }
    }
}

static void sql_query_callback(struct sql_result *sql_result,
                   struct userdb_sql_request *sql_request)
{
    struct auth_request *auth_request = sql_request->auth_request;
    struct userdb_module *_module = auth_request->userdb->userdb;
    struct sql_userdb_module *module =
        (struct sql_userdb_module *)_module;
    enum userdb_result result = USERDB_RESULT_INTERNAL_FAILURE;
    int ret;

    ret = sql_result_next_row(sql_result);
    if (ret >= 0)
        db_sql_success(module->conn);
    if (ret < 0) {
        if (!module->conn->default_user_query) {
            auth_request_log_error(auth_request, AUTH_SUBSYS_DB,
                "User query failed: %s",
                sql_result_get_error(sql_result));
        } else {
            auth_request_log_error(auth_request, AUTH_SUBSYS_DB,
                "User query failed: %s "
                "(using built-in default user_query: %s)",
                sql_result_get_error(sql_result),
                module->conn->set.user_query);
        }
    } else if (ret == 0) {
        result = USERDB_RESULT_USER_UNKNOWN;
        auth_request_log_unknown_user(auth_request, AUTH_SUBSYS_DB);
    } else {
        sql_query_get_result(sql_result, auth_request);
        result = USERDB_RESULT_OK;
    }

    sql_request->callback(result, auth_request);
    auth_request_unref(&auth_request);
    i_free(sql_request);
}

static const char *
userdb_sql_escape(const char *str, const struct auth_request *auth_request)
{
    struct userdb_module *_module = auth_request->userdb->userdb;
    struct sql_userdb_module *module =
        (struct sql_userdb_module *)_module;

    return sql_escape_string(module->conn->db, str);
}

static void userdb_sql_lookup(struct auth_request *auth_request,
                  userdb_callback_t *callback)
{
    struct userdb_module *_module = auth_request->userdb->userdb;
    struct sql_userdb_module *module =
        (struct sql_userdb_module *)_module;
    struct userdb_sql_request *sql_request;
    const char *query, *error;

    if (t_auth_request_var_expand(module->conn->set.user_query,
                      auth_request, userdb_sql_escape,
                      &query, &error) <= 0) {
        auth_request_log_error(auth_request, AUTH_SUBSYS_DB,
            "Failed to expand user_query=%s: %s",
            module->conn->set.user_query, error);
        callback(USERDB_RESULT_INTERNAL_FAILURE, auth_request);
        return;
    }

    auth_request_ref(auth_request);
    sql_request = i_new(struct userdb_sql_request, 1);
    sql_request->callback = callback;
    sql_request->auth_request = auth_request;

    auth_request_log_debug(auth_request, AUTH_SUBSYS_DB, "%s", query);

    sql_query(module->conn->db, query,
          sql_query_callback, sql_request);
}

static void sql_iter_query_callback(struct sql_result *sql_result,
                    struct sql_userdb_iterate_context *ctx)
{
    ctx->result = sql_result;
    sql_result_ref(sql_result);

    if (ctx->freed)
        (void)userdb_sql_iterate_deinit(&ctx->ctx);
    else if (ctx->call_iter)
        userdb_sql_iterate_next(&ctx->ctx);
}

static struct userdb_iterate_context *
userdb_sql_iterate_init(struct auth_request *auth_request,
            userdb_iter_callback_t *callback, void *context)
{
    struct userdb_module *_module = auth_request->userdb->userdb;
    struct sql_userdb_module *module =
        (struct sql_userdb_module *)_module;
    struct sql_userdb_iterate_context *ctx;
    const char *query, *error;

    if (t_auth_request_var_expand(module->conn->set.iterate_query,
                      auth_request, userdb_sql_escape,
                      &query, &error) <= 0) {
        auth_request_log_error(auth_request, AUTH_SUBSYS_DB,
            "Failed to expand iterate_query=%s: %s",
            module->conn->set.iterate_query, error);
    }

    ctx = i_new(struct sql_userdb_iterate_context, 1);
    ctx->ctx.auth_request = auth_request;
    ctx->ctx.callback = callback;
    ctx->ctx.context = context;
    auth_request_ref(auth_request);

    sql_query(module->conn->db, query,
          sql_iter_query_callback, ctx);
    auth_request_log_debug(auth_request, AUTH_SUBSYS_DB, "%s", query);
    return &ctx->ctx;
}

static int userdb_sql_iterate_get_user(struct sql_userdb_iterate_context *ctx,
                       const char **user_r)
{
    const char *domain;
    int idx;

    /* try user first */
    idx = sql_result_find_field(ctx->result, "user");
    if (idx == 0) {
        *user_r = sql_result_get_field_value(ctx->result, idx);
        return 0;
    }

    /* username [+ domain]? */
    idx = sql_result_find_field(ctx->result, "username");
    if (idx < 0) {
        /* no user or username, fail */
        return -1;
    }

    *user_r = sql_result_get_field_value(ctx->result, idx);
    if (*user_r == NULL)
        return 0;

    domain = sql_result_find_field_value(ctx->result, "domain");
    if (domain != NULL)
        *user_r = t_strconcat(*user_r, "@", domain, NULL);
    return 0;
}

static void userdb_sql_iterate_next(struct userdb_iterate_context *_ctx)
{
    struct sql_userdb_iterate_context *ctx =
        (struct sql_userdb_iterate_context *)_ctx;
    struct userdb_module *_module = _ctx->auth_request->userdb->userdb;
    struct sql_userdb_module *module = (struct sql_userdb_module *)_module;
    const char *user;
    int ret;

    if (ctx->result == NULL) {
        /* query not finished yet */
        ctx->call_iter = TRUE;
        return;
    }

    ret = sql_result_next_row(ctx->result);
    if (ret >= 0)
        db_sql_success(module->conn);
    if (ret > 0) {
        if (userdb_sql_iterate_get_user(ctx, &user) < 0)
            i_error("sql: Iterate query didn't return 'user' field");
        else if (user == NULL)
            i_error("sql: Iterate query returned NULL user");
        else {
            _ctx->callback(user, _ctx->context);
            return;
        }
        _ctx->failed = TRUE;
    } else if (ret < 0) {
        if (!module->conn->default_iterate_query) {
            i_error("sql: Iterate query failed: %s",
                sql_result_get_error(ctx->result));
        } else {
            i_error("sql: Iterate query failed: %s "
                "(using built-in default iterate_query: %s)",
                sql_result_get_error(ctx->result),
                module->conn->set.iterate_query);
        }
        _ctx->failed = TRUE;
    }
    _ctx->callback(NULL, _ctx->context);
}

static int userdb_sql_iterate_deinit(struct userdb_iterate_context *_ctx)
{
    struct sql_userdb_iterate_context *ctx =
        (struct sql_userdb_iterate_context *)_ctx;
    int ret = _ctx->failed ? -1 : 0;

    auth_request_unref(&_ctx->auth_request);
    if (ctx->result == NULL) {
        /* sql query hasn't finished yet */
        ctx->freed = TRUE;
    } else {
        if (ctx->result != NULL)
            sql_result_unref(ctx->result);
        i_free(ctx);
    }
    return ret;
}

static struct userdb_module *
userdb_sql_preinit(pool_t pool, const char *args)
{
    struct sql_userdb_module *module;

    module = p_new(pool, struct sql_userdb_module, 1);
    module->conn = db_sql_init(args, TRUE);

    module->module.default_cache_key =
        auth_cache_parse_key(pool, module->conn->set.user_query);
    return &module->module;
}

static void userdb_sql_init(struct userdb_module *_module)
{
    struct sql_userdb_module *module =
        (struct sql_userdb_module *)_module;
    enum sql_db_flags flags;

    flags = sql_get_flags(module->conn->db);
    _module->blocking = (flags & SQL_DB_FLAG_BLOCKING) != 0;

    if (!_module->blocking || worker)
        db_sql_connect(module->conn);
}

static void userdb_sql_deinit(struct userdb_module *_module)
{
    struct sql_userdb_module *module =
        (struct sql_userdb_module *)_module;

    db_sql_unref(&module->conn);
}

struct userdb_module_interface userdb_sql = {
    "sql",

    userdb_sql_preinit,
    userdb_sql_init,
    userdb_sql_deinit,

    userdb_sql_lookup,

    userdb_sql_iterate_init,
    userdb_sql_iterate_next,
    userdb_sql_iterate_deinit
};
#else
struct userdb_module_interface userdb_sql = {
    .name = "sql"
};
#endif