/*
   SSSD

   Data Provider, private header file

   Copyright (C) Simo Sorce <ssorce@redhat.com>	2008

   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/>.
*/

#ifndef __DP_BACKEND_H__
#define __DP_BACKEND_H__

#include "providers/data_provider.h"
#include "providers/fail_over.h"
#include "providers/dp_refresh.h"
#include "util/child_common.h"
#include "db/sysdb.h"

/* a special token, if used in place of the hostname, denotes that real
 * hostnames should be looked up from DNS using SRV requests
 */
#define BE_SRV_IDENTIFIER  "_srv_"

struct be_ctx;
struct bet_ops;
struct be_req;

typedef int (*bet_init_fn_t)(TALLOC_CTX *, struct bet_ops **, void **);
typedef void (*be_shutdown_fn)(void *);
typedef void (*be_req_fn_t)(struct be_req *);
typedef void (*be_async_callback_t)(struct be_req *, int, int, const char *);

typedef void (*be_callback_t)(void *);

enum bet_type {
    BET_NULL = 0,
    BET_ID,
    BET_AUTH,
    BET_ACCESS,
    BET_CHPASS,
    BET_SUDO,
    BET_AUTOFS,
    BET_SELINUX,
    BET_HOSTID,
    BET_SUBDOMAINS,
    BET_MAX
};

struct bet_data {
    enum bet_type bet_type;
    const char *option_name;
    const char *mod_init_fn_name_fmt;
};

struct loaded_be {
    char *be_name;
    void *handle;
};

struct bet_queue_item {
    struct bet_queue_item *prev;
    struct bet_queue_item *next;

    TALLOC_CTX *mem_ctx;
    struct be_req *be_req;
    be_req_fn_t fn;

};

struct bet_info {
    enum bet_type bet_type;
    struct bet_ops *bet_ops;
    void *pvt_bet_data;
    char *mod_name;
    struct bet_queue_item *req_queue;
};

struct be_offline_status {
    time_t went_offline;
    bool offline;
};

struct be_resolv_ctx {
    struct resolv_ctx *resolv;
    struct dp_option *opts;

    enum restrict_family family_order;
};

struct be_client {
    struct be_ctx *bectx;
    struct sbus_connection *conn;
    struct tevent_timer *timeout;
    bool initialized;
};

struct be_failover_ctx;

struct be_cb;

struct be_ctx {
    struct tevent_context *ev;
    struct confdb_ctx *cdb;
    struct sss_domain_info *domain;
    const char *identity;
    const char *conf_path;
    struct be_failover_ctx *be_fo;
    struct be_resolv_ctx *be_res;

    /* Functions to be invoked when the
     * backend goes online or offline
     */
    struct be_cb *online_cb_list;
    bool run_online_cb;
    struct be_cb *offline_cb_list;
    struct be_cb *reconnect_cb_list;
    /* In contrast to online_cb_list which are only run if the backend is
     * offline the unconditional_online_cb_list should be run whenever the
     * backend receives a request to go online. The typical use case is to
     * reset timers independenly of the state of the backend. */
    struct be_cb *unconditional_online_cb_list;

    struct be_offline_status offstat;

    struct sbus_connection *mon_conn;
    struct sbus_connection *sbus_srv;

    struct be_client *nss_cli;
    struct be_client *pam_cli;
    struct be_client *sudo_cli;
    struct be_client *autofs_cli;
    struct be_client *ssh_cli;
    struct be_client *pac_cli;

    struct loaded_be loaded_be[BET_MAX];
    struct bet_info bet_info[BET_MAX];

    struct be_refresh_ctx *refresh_ctx;

    size_t check_online_ref_count;

    /* List of ongoing requests */
    struct be_req *active_requests;
};

struct bet_ops {
    be_req_fn_t check_online;
    be_req_fn_t handler;
    be_req_fn_t finalize;
};

struct be_acct_req {
    int entry_type;
    int attr_type;
    int filter_type;
    char *filter_value;
    char *extra_value;
    char *domain;
};

struct be_sudo_req {
    uint32_t type;
    char **rules;
};

struct be_autofs_req {
    char *mapname;
    bool invalidate;
};

struct be_subdom_req {
    bool force;
    char *domain_hint;
};

struct be_host_req {
    uint32_t type;
    int filter_type;
    char *name;
    char *alias;
};

bool be_is_offline(struct be_ctx *ctx);
void be_mark_offline(struct be_ctx *ctx);

int be_add_reconnect_cb(TALLOC_CTX *mem_ctx,
                        struct be_ctx *ctx,
                        be_callback_t cb,
                        void *pvt,
                        struct be_cb **reconnect_cb);
void be_run_reconnect_cb(struct be_ctx *be);

int be_add_online_cb(TALLOC_CTX *mem_ctx,
                     struct be_ctx *ctx,
                     be_callback_t cb,
                     void *pvt,
                     struct be_cb **online_cb);
void be_run_online_cb(struct be_ctx *be);
int be_add_unconditional_online_cb(TALLOC_CTX *mem_ctx, struct be_ctx *ctx,
                                   be_callback_t cb, void *pvt,
                                   struct be_cb **unconditional_online_cb);
void be_run_unconditional_online_cb(struct be_ctx *be);

int be_add_offline_cb(TALLOC_CTX *mem_ctx,
                     struct be_ctx *ctx,
                     be_callback_t cb,
                     void *pvt,
                     struct be_cb **online_cb);
void be_run_offline_cb(struct be_ctx *be);

/* from data_provider_fo.c */
enum be_fo_protocol {
    BE_FO_PROTO_TCP,
    BE_FO_PROTO_UDP,
    BE_FO_PROTO_SENTINEL
};

typedef void (be_svc_callback_fn_t)(void *, struct fo_server *);

int be_init_failover(struct be_ctx *ctx);
int be_fo_is_srv_identifier(const char *server);
int be_fo_add_service(struct be_ctx *ctx, const char *service_name,
                      datacmp_fn user_data_cmp);
int be_fo_service_add_callback(TALLOC_CTX *memctx,
                               struct be_ctx *ctx, const char *service_name,
                               be_svc_callback_fn_t *fn, void *private_data);
int be_fo_get_server_count(struct be_ctx *ctx, const char *service_name);

void be_fo_set_srv_lookup_plugin(struct be_ctx *ctx,
                                 fo_srv_lookup_plugin_send_t send_fn,
                                 fo_srv_lookup_plugin_recv_t recv_fn,
                                 void *pvt,
                                 const char *plugin_name);

errno_t be_fo_set_dns_srv_lookup_plugin(struct be_ctx *be_ctx,
                                        const char *hostname);

int be_fo_add_srv_server(struct be_ctx *ctx,
                         const char *service_name,
                         const char *query_service,
                         const char *default_discovery_domain,
                         enum be_fo_protocol proto,
                         bool proto_fallback, void *user_data);
int be_fo_add_server(struct be_ctx *ctx, const char *service_name,
                     const char *server, int port, void *user_data,
                     bool primary);

struct tevent_req *be_resolve_server_send(TALLOC_CTX *memctx,
                                          struct tevent_context *ev,
                                          struct be_ctx *ctx,
                                          const char *service_name,
                                          bool first_try);
int be_resolve_server_recv(struct tevent_req *req, struct fo_server **srv);

void be_fo_set_port_status(struct be_ctx *ctx,
                           const char *service_name,
                           struct fo_server *server,
                           enum port_status status);

/*
 * Instruct fail-over to try next server on the next connect attempt.
 * Should be used after connection to service was unexpectedly dropped
 * but there is no authoritative information on whether active server is down.
 */
void be_fo_try_next_server(struct be_ctx *ctx, const char *service_name);

int be_fo_run_callbacks_at_next_request(struct be_ctx *ctx,
                                        const char *service_name);

void reset_fo(struct be_ctx *be_ctx);

errno_t be_res_init(struct be_ctx *ctx);

/* be_req helpers */

struct be_req *be_req_create(TALLOC_CTX *mem_ctx,
                             struct be_client *becli, struct be_ctx *be_ctx,
                             be_async_callback_t fn, void *pvt_fn_data);
struct be_ctx *be_req_get_be_ctx(struct be_req *be_req);

void *be_req_get_data(struct be_req *be_req);

void be_req_terminate(struct be_req *be_req,
                      int dp_err_type, int errnum, const char *errstr);

void be_terminate_domain_requests(struct be_ctx *be_ctx,
                                  const char *domain);

/* Request account information */
struct tevent_req *
be_get_account_info_send(TALLOC_CTX *mem_ctx,
                         struct tevent_context *ev,
                         struct be_client *becli,
                         struct be_ctx *be_ctx,
                         struct be_acct_req *ar);

errno_t be_get_account_info_recv(struct tevent_req *req,
                                 TALLOC_CTX *mem_ctx,
                                 int *_err_maj,
                                 int *_err_min,
                                 const char **_err_msg);

#endif /* __DP_BACKEND_H___ */