#ifndef _GPRS_SGSN_H
#define _GPRS_SGSN_H

#include <stdint.h>
#include <netinet/in.h>

#include <osmocom/core/timer.h>

#include <osmocom/gsm/gsm48.h>

#include <osmocom/crypt/gprs_cipher.h>

#include <openbsc/gsm_data.h>

#define GSM_IMSI_LENGTH 17
#define GSM_IMEI_LENGTH 17
#define GSM_EXTENSION_LENGTH 15

struct gprs_llc_lle;
struct ctrl_handle;
struct gsm_subscriber;

/* TS 04.08 4.1.3.3 GMM mobility management states on the network side */
enum gprs_mm_state {
	GMM_DEREGISTERED,		/* 4.1.3.3.1.1 */
	GMM_COMMON_PROC_INIT,		/* 4.1.3.3.1.2 */
	GMM_REGISTERED_NORMAL,		/* 4.1.3.3.2.1 */
	GMM_REGISTERED_SUSPENDED,	/* 4.1.3.3.2.2 */
	GMM_DEREGISTERED_INIT,		/* 4.1.3.3.1.4 */
};

enum gprs_mm_ctr {
	GMM_CTR_PKTS_SIG_IN,
	GMM_CTR_PKTS_SIG_OUT,
	GMM_CTR_PKTS_UDATA_IN,
	GMM_CTR_PKTS_UDATA_OUT,
	GMM_CTR_BYTES_UDATA_IN,
	GMM_CTR_BYTES_UDATA_OUT,
	GMM_CTR_PDP_CTX_ACT,
	GMM_CTR_SUSPEND,
	GMM_CTR_PAGING_PS,
	GMM_CTR_PAGING_CS,
	GMM_CTR_RA_UPDATE,
};

enum gprs_pdp_ctx {
	PDP_CTR_PKTS_UDATA_IN,
	PDP_CTR_PKTS_UDATA_OUT,
	PDP_CTR_BYTES_UDATA_IN,
	PDP_CTR_BYTES_UDATA_OUT,
};

enum gprs_t3350_mode {
	GMM_T3350_MODE_NONE,
	GMM_T3350_MODE_ATT,
	GMM_T3350_MODE_RAU,
	GMM_T3350_MODE_PTMSI_REALL,
};

/* Authorization/ACL handling */
enum sgsn_auth_state {
	SGSN_AUTH_UNKNOWN,
	SGSN_AUTH_AUTHENTICATE,
	SGSN_AUTH_ACCEPTED,
	SGSN_AUTH_REJECTED
};

#define MS_RADIO_ACCESS_CAPA

/* According to TS 03.60, Table 5: SGSN MM and PDP Contexts */
/* Extended by 3GPP TS 23.060, Table 6: SGSN MM and PDP Contexts */
struct sgsn_mm_ctx {
	struct llist_head	list;

	char 			imsi[GSM_IMSI_LENGTH];
	enum gprs_mm_state	mm_state;
	uint32_t 		p_tmsi;
	uint32_t 		p_tmsi_old;	/* old P-TMSI before new is confirmed */
	uint32_t 		p_tmsi_sig;
	char 			imei[GSM_IMEI_LENGTH];
	/* Opt: Software Version Numbber / TS 23.195 */
	char 			msisdn[GSM_EXTENSION_LENGTH];
	struct gprs_ra_id	ra;
	uint16_t		cell_id;
	uint32_t		cell_id_age;
	uint16_t		sac;	/* Iu: Service Area Code */
	uint32_t		sac_age;/* Iu: Service Area Code age */
	/* VLR number */
	uint32_t		new_sgsn_addr;
	/* Authentication Triplet */
	struct gsm_auth_tuple	auth_triplet;
	/* Kc */
	/* Iu: CK, IK, KSI */
	/* CKSN */
	enum gprs_ciph_algo	ciph_algo;
	struct {
		uint8_t	len;
		uint8_t	buf[50];	/* GSM 04.08 10.5.5.12a, extended in TS 24.008 */
	} ms_radio_access_capa;
	struct {
		uint8_t	len;
		uint8_t	buf[8];		/* GSM 04.08 10.5.5.12, extended in TS 24.008 */
	} ms_network_capa;
	uint16_t		drx_parms;
	int			mnrg;	/* MS reported to HLR? */
	int			ngaf;	/* MS reported to MSC/VLR? */
	int			ppf;	/* paging for GPRS + non-GPRS? */
	/* SMS Parameters */
	int			recovery;
	uint8_t			radio_prio_sms;

	struct llist_head	pdp_list;

	/* Additional bits not present in the GSM TS */
	struct gprs_llc_llme	*llme;
	uint32_t		tlli;
	uint32_t		tlli_new;
	uint16_t		nsei;
	uint16_t		bvci;
	struct rate_ctr_group	*ctrg;
	struct osmo_timer_list	timer;
	unsigned int		T;		/* Txxxx number */
	unsigned int		num_T_exp;	/* number of consecutive T expirations */

	enum gprs_t3350_mode	t3350_mode;
	uint8_t			t3370_id_type;
	uint8_t			pending_req;	/* the request's message type */
	/* TODO: There isn't much semantic difference between t3350_mode
	 * (refers to the timer) and pending_req (refers to the procedure),
	 * where mm->T == 3350 => mm->t3350_mode == f(mm->pending_req). Check
	 * whether one of them can be dropped. */

	enum sgsn_auth_state	auth_state;
	int			is_authenticated;

	struct gsm_subscriber   *subscr;
};

#define LOGMMCTXP(level, mm, fmt, args...) \
	LOGP(DMM, level, "MM(%s/%08x) " fmt, (mm) ? (mm)->imsi : "---", \
	     (mm) ? (mm)->p_tmsi : GSM_RESERVED_TMSI, ## args)

/* look-up a SGSN MM context based on TLLI + RAI */
struct sgsn_mm_ctx *sgsn_mm_ctx_by_tlli(uint32_t tlli,
					const struct gprs_ra_id *raid);
struct sgsn_mm_ctx *sgsn_mm_ctx_by_ptmsi(uint32_t tmsi);
struct sgsn_mm_ctx *sgsn_mm_ctx_by_imsi(const char *imsi);

/* Allocate a new SGSN MM context */
struct sgsn_mm_ctx *sgsn_mm_ctx_alloc(uint32_t tlli,
					const struct gprs_ra_id *raid);
void sgsn_mm_ctx_free(struct sgsn_mm_ctx *mm);


enum pdp_ctx_state {
	PDP_STATE_NONE,
	PDP_STATE_CR_REQ,
	PDP_STATE_CR_CONF,

	/* 04.08 / Figure 6.2 / 6.1.2.2 */
	PDP_STATE_INACT_PEND,
	PDP_STATE_INACTIVE = PDP_STATE_NONE,
};

enum pdp_type {
	PDP_TYPE_NONE,
	PDP_TYPE_ETSI_PPP,
	PDP_TYPE_IANA_IPv4,
	PDP_TYPE_IANA_IPv6,
};

struct sgsn_pdp_ctx {
	struct llist_head	list;	/* list_head for mmctx->pdp_list */
	struct llist_head	g_list;	/* list_head for global list */
	struct sgsn_mm_ctx	*mm;	/* back pointer to MM CTX */
	struct sgsn_ggsn_ctx	*ggsn;	/* which GGSN serves this PDP */
	struct rate_ctr_group	*ctrg;

	//unsigned int		id;
	struct pdp_t		*lib;	/* pointer to libgtp PDP ctx */
	enum pdp_ctx_state	state;
	enum pdp_type		type;
	uint32_t		address;
	char 			*apn_subscribed;
	//char 			*apn_used;
	uint16_t		nsapi;	/* SNDCP */
	uint16_t		sapi;	/* LLC */
	uint8_t			ti;	/* transaction identifier */
	int			vplmn_allowed;
	uint32_t		qos_profile_subscr;
	//uint32_t		qos_profile_req;
	//uint32_t		qos_profile_neg;
	uint8_t			radio_prio;
	uint32_t		tx_npdu_nr;
	uint32_t		rx_npdu_nr;
	uint32_t		tx_gtp_snd;
	uint32_t		rx_gtp_snu;
	//uint32_t		charging_id;
	int			reordering_reqd;

	struct osmo_timer_list	timer;
	unsigned int		T;		/* Txxxx number */
	unsigned int		num_T_exp;	/* number of consecutive T expirations */
};

#define LOGPDPCTXP(level, pdp, fmt, args...) \
	LOGP(DGPRS, level, "PDP(%s/%u) " \
	     fmt, (pdp)->mm ? (pdp)->mm->imsi : "---", (pdp)->ti, ## args)

/* look up PDP context by MM context and NSAPI */
struct sgsn_pdp_ctx *sgsn_pdp_ctx_by_nsapi(const struct sgsn_mm_ctx *mm,
					   uint8_t nsapi);
/* look up PDP context by MM context and transaction ID */
struct sgsn_pdp_ctx *sgsn_pdp_ctx_by_tid(const struct sgsn_mm_ctx *mm,
					 uint8_t tid);

struct sgsn_pdp_ctx *sgsn_pdp_ctx_alloc(struct sgsn_mm_ctx *mm,
					uint8_t nsapi);
void sgsn_pdp_ctx_terminate(struct sgsn_pdp_ctx *pdp);
void sgsn_pdp_ctx_free(struct sgsn_pdp_ctx *pdp);


struct sgsn_ggsn_ctx {
	struct llist_head list;
	uint32_t id;
	unsigned int gtp_version;
	struct in_addr remote_addr;
	int remote_restart_ctr;
	struct gsn_t *gsn;
};
struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_alloc(uint32_t id);
struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_by_id(uint32_t id);
struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_by_addr(struct in_addr *addr);
struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_find_alloc(uint32_t id);

struct apn_ctx {
	struct llist_head list;
	struct sgsn_ggsn_ctx *ggsn;
	char *name;
	char *description;
};

extern struct llist_head sgsn_mm_ctxts;
extern struct llist_head sgsn_ggsn_ctxts;
extern struct llist_head sgsn_apn_ctxts;
extern struct llist_head sgsn_pdp_ctxts;

uint32_t sgsn_alloc_ptmsi(void);

/* High-level function to be called in case a GGSN has disappeared or
 * ottherwise lost state (recovery procedure) */
int drop_all_pdp_for_ggsn(struct sgsn_ggsn_ctx *ggsn);

char *gprs_pdpaddr2str(uint8_t *pdpa, uint8_t len);

/* Force re-attachment based on msgb meta data */
int sgsn_force_reattach_oldmsg(struct msgb *oldmsg);

/*
 * ctrl interface related work
 */
struct gsm_network;
struct ctrl_handle *sgsn_controlif_setup(struct gsm_network *, uint16_t port);
int sgsn_ctrl_cmds_install(void);

/*
 * Authorization/ACL handling
 */
struct imsi_acl_entry {
	struct llist_head list;
	char imsi[16+1];
};

struct sgsn_subscriber_data {
	struct sgsn_mm_ctx	*mm;
	struct gsm_auth_tuple	auth_triplets[5];
	int			auth_triplets_updated;
	int			error_cause;
	struct osmo_timer_list	timer;
};

#define LOGGSUBSCRP(level, subscr, fmt, args...) \
	LOGP(DGPRS, level, "SUBSCR(%s) " fmt, (subscr)->imsi, \
	     ## args)

struct sgsn_config;
struct sgsn_instance;
extern const struct value_string *sgsn_auth_state_names;

void sgsn_auth_init(void);
struct imsi_acl_entry *sgsn_acl_lookup(const char *imsi, struct sgsn_config *cfg);
int sgsn_acl_add(const char *imsi, struct sgsn_config *cfg);
int sgsn_acl_del(const char *imsi, struct sgsn_config *cfg);
/* Request authorization */
int sgsn_auth_request(struct sgsn_mm_ctx *mm);
enum sgsn_auth_state sgsn_auth_state(struct sgsn_mm_ctx *mm);
void sgsn_auth_update(struct sgsn_mm_ctx *mm);
struct gsm_auth_tuple *sgsn_auth_get_tuple(struct sgsn_mm_ctx *mmctx,
					   unsigned key_seq);

/*
 * GPRS subscriber data
 */
#define GPRS_SUBSCRIBER_UPDATE_AUTH_INFO_PENDING	(1 << 16)
#define GPRS_SUBSCRIBER_UPDATE_LOCATION_PENDING		(1 << 17)
#define GPRS_SUBSCRIBER_CANCELLED			(1 << 18)
#define GPRS_SUBSCRIBER_ENABLE_PURGE			(1 << 19)

#define GPRS_SUBSCRIBER_UPDATE_PENDING_MASK ( \
		GPRS_SUBSCRIBER_UPDATE_LOCATION_PENDING | \
		GPRS_SUBSCRIBER_UPDATE_AUTH_INFO_PENDING  \
)

int gprs_subscr_init(struct sgsn_instance *sgi);
int gprs_subscr_request_update_location(struct sgsn_mm_ctx *mmctx);
int gprs_subscr_request_auth_info(struct sgsn_mm_ctx *mmctx);
void gprs_subscr_delete(struct gsm_subscriber *subscr);
struct gsm_subscriber *gprs_subscr_get_or_create(const char *imsi);
struct gsm_subscriber *gprs_subscr_get_or_create_by_mmctx( struct sgsn_mm_ctx *mmctx);
struct gsm_subscriber *gprs_subscr_get_by_imsi(const char *imsi);
void gprs_subscr_put_and_cancel(struct gsm_subscriber *subscr);
void gprs_subscr_update(struct gsm_subscriber *subscr);
void gprs_subscr_update_auth_info(struct gsm_subscriber *subscr);
int gprs_subscr_rx_gsup_message(struct msgb *msg);

/* Called on subscriber data updates */
void sgsn_update_subscriber_data(struct sgsn_mm_ctx *mmctx,
				 struct gsm_subscriber *subscr);

int gprs_sndcp_vty_init(void);
struct sgsn_instance;
int sgsn_gtp_init(struct sgsn_instance *sgi);

#endif /* _GPRS_SGSN_H */