Add libvlr implementation

Original libvlr code is by Harald Welte <laforge@gnumonks.org>,
polished and tweaked by Neels Hofmeyr <nhofmeyr@sysmocom.de>.

This is a long series of trial-and-error development collapsed in one patch.
This may be split in smaller commits if reviewers prefer that. If we can keep
it as one, we have saved ourselves the additional separation work.

Related: OS#1592
Change-Id: Ie303c98f8c18e40c87c1b68474b35de332033622

4 files changed, 415 insertions, 9 deletions

diff --git a/include/openbsc/Makefile.am b/include/openbsc/Makefile.am
index 2740a5d07..532328cb7 100644
--- a/include/openbsc/Makefile.am
+++ b/include/openbsc/Makefile.am
@@ -84,6 +84,7 @@ noinst_HEADERS = \
 	trau_mux.h \
 	trau_upqueue.h \
 	ussd.h \
+	vlr.h \
 	vty.h \
 	v42bis.h \
 	v42bis_private.h \
diff --git a/include/openbsc/debug.h b/include/openbsc/debug.h
index 8a4247b69..3feb7c3fc 100644
--- a/include/openbsc/debug.h
+++ b/include/openbsc/debug.h
@@ -38,12 +38,8 @@ enum {
 	DSUA,
 	DV42BIS,
 	DPCU,
+	DVLR,
 	Debug_LastEntry,
 };
 
-struct gsm_subscriber;
-
-void log_set_filter_vlr_subscr(struct log_target *target,
-			       struct gsm_subscriber *vlr_subscr);
-
 extern const struct log_info log_info;
diff --git a/include/openbsc/iu.h b/include/openbsc/iu.h
index f973ac1ba..8cf830ef0 100644
--- a/include/openbsc/iu.h
+++ b/include/openbsc/iu.h
@@ -22,9 +22,6 @@ enum iu_event_type {
 	IU_EVENT_SECURITY_MODE_COMPLETE,
 	IU_EVENT_IU_RELEASE, /* An actual Iu Release message was received */
 	IU_EVENT_LINK_INVALIDATED, /* A SUA link was lost or closed down */
-	/* FIXME: maybe IU_EVENT_IU_RELEASE and IU_EVENT_LINK_INVALIDATED
-	 * should be combined to one generic event that simply means the
-	 * ue_conn_ctx should no longer be used, for whatever reason. */
 };
 
 extern const struct value_string iu_event_type_names[];
@@ -35,7 +32,6 @@ static inline const char *iu_event_type_str(enum iu_event_type e)
 
 /* Implementations of iu_recv_cb_t shall find the ue_conn_ctx in msg->dst. */
 typedef int (* iu_recv_cb_t )(struct msgb *msg, struct gprs_ra_id *ra_id,
-			      /* TODO "gprs_" in generic CS+PS domain ^ */
 			      uint16_t *sai);
 
 typedef int (* iu_event_cb_t )(struct ue_conn_ctx *ue_ctx,
diff --git a/include/openbsc/vlr.h b/include/openbsc/vlr.h
new file mode 100644
index 000000000..90e3d7a11
--- /dev/null
+++ b/include/openbsc/vlr.h
@@ -0,0 +1,413 @@
+#pragma once
+
+#include <stdint.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/fsm.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/gsm/protocol/gsm_23_003.h>
+#include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
+#include <osmocom/gsm/gsm23003.h>
+#include <openbsc/gsm_data.h>
+// for GSM_NAME_LENGTH
+#include <openbsc/gsm_subscriber.h>
+
+/* from 3s to 10s */
+#define GSM_29002_TIMER_S	10
+/* from 15s to 30s */
+#define GSM_29002_TIMER_M	30
+/* from 1min to 10min */
+#define GSM_29002_TIMER_ML	(10*60)
+/* from 28h to 38h */
+#define GSM_29002_TIMER_L	(32*60*60)
+
+
+/* VLR subscriber authentication state */
+enum vlr_subscr_auth_state {
+	/* subscriber needs to be autenticated */
+	VLR_SUB_AS_NEEDS_AUTH,
+	/* waiting for AuthInfo from HLR/AUC */
+	VLR_SUB_AS_NEEDS_AUTH_WAIT_AI,
+	/* waiting for response from subscriber */
+	VLR_SUB_AS_WAIT_RESP,
+	/* successfully authenticated */
+	VLR_SUB_AS_AUTHENTICATED,
+	/* subscriber needs re-sync */
+	VLR_SUB_AS_NEEDS_RESYNC,
+	/* waiting for AuthInfo with ReSync */
+	VLR_SUB_AS_NEEDS_AUTH_WAIT_SAI_RESYNC,
+	/* waiting for response from subscr, resync case */
+	VLR_SUB_AS_WAIT_RESP_RESYNC,
+	/* waiting for IMSI from subscriber */
+	VLR_SUB_AS_WAIT_ID_IMSI,
+	/* authentication has failed */
+	VLR_SUB_AS_AUTH_FAILED,
+};
+
+enum vlr_lu_event {
+	VLR_ULA_E_UPDATE_LA,	/* Initial trigger (LU from MS) */
+	VLR_ULA_E_SEND_ID_ACK,	/* Result of Send-ID from PVLR */
+	VLR_ULA_E_SEND_ID_NACK,	/* Result of Send-ID from PVLR */
+	VLR_ULA_E_AUTH_RES,	/* Result of auth procedure */
+	VLR_ULA_E_CIPH_RES,	/* Result of Ciphering Mode Command */
+	VLR_ULA_E_ID_IMSI,	/* IMSI recieved from MS */
+	VLR_ULA_E_ID_IMEI,	/* IMEI received from MS */
+	VLR_ULA_E_ID_IMEISV,	/* IMEISV received from MS */
+	VLR_ULA_E_HLR_LU_RES,	/* HLR UpdateLocation result */
+	VLR_ULA_E_UPD_HLR_COMPL,/* UpdatE_HLR_VLR result */
+	VLR_ULA_E_LU_COMPL_SUCCESS,/* Location_Update_Completion_VLR result */
+	VLR_ULA_E_LU_COMPL_FAILURE,/* Location_Update_Completion_VLR result */
+	VLR_ULA_E_NEW_TMSI_ACK,	/* TMSI Reallocation Complete */
+};
+
+enum vlr_ciph_result_cause {
+	VLR_CIPH_REJECT, /* ? */
+	VLR_CIPH_COMPL,
+};
+
+struct vlr_ciph_result {
+	enum vlr_ciph_result_cause cause;
+	const char *imeisv;
+};
+
+enum vlr_subscr_security_context {
+	VLR_SEC_CTX_NONE,
+	VLR_SEC_CTX_GSM,
+	VLR_SEC_CTX_UMTS,
+};
+
+enum vlr_lu_type {
+	VLR_LU_TYPE_PERIODIC,
+	VLR_LU_TYPE_IMSI_ATTACH,
+	VLR_LU_TYPE_REGULAR,
+};
+
+#define OSMO_LBUF_DECL(name, xlen)		\
+	struct {				\
+		uint8_t buf[xlen];		\
+		size_t len;			\
+	} name
+
+struct sgsn_mm_ctx;
+struct vlr_instance;
+
+/* The VLR subscriber is the part of the GSM subscriber state in VLR (CS) or
+ * SGSN (PS), particularly while interacting with the HLR via GSUP */
+struct vlr_subscr {
+	struct llist_head list;
+	struct vlr_instance *vlr;
+
+	/* TODO either populate from HLR or drop this completely? */
+	long long unsigned int id;
+
+	/* Data from HLR */				/* 3GPP TS 23.008 */
+	/* Always use vlr_subscr_set_imsi() to write to imsi[] */
+	char imsi[GSM23003_IMSI_MAX_DIGITS+1];		/* 2.1.1.1 */
+	char msisdn[GSM_EXTENSION_LENGTH+1];		/* 2.1.2 */
+	char name[GSM_NAME_LENGTH+1];			/* proprietary */
+	OSMO_LBUF_DECL(hlr, 16);			/* 2.4.7 */
+	uint32_t periodic_lu_timer;			/* 2.4.24 */
+	uint32_t age_indicator;				/* 2.17.1 */
+
+	/* Authentication Data */
+	struct gsm_auth_tuple auth_tuples[5];		/* 2.3.1-2.3.4 */
+	struct gsm_auth_tuple *last_tuple;
+	enum vlr_subscr_security_context sec_ctx;
+
+	/* Data local to VLR is below */
+	uint32_t tmsi;					/* 2.1.4 */
+	/* Newly allocated TMSI that was not yet acked by MS */
+	uint32_t tmsi_new;
+
+	/* some redundancy in information below? */
+	struct osmo_cell_global_id cgi;			/* 2.4.16 */
+	uint16_t lac;					/* 2.4.2 */
+
+	char imeisv[GSM23003_IMEISV_NUM_DIGITS+1];	/* 2.2.3 */
+	char imei[GSM23003_IMEISV_NUM_DIGITS+1];	/* 2.1.9 */
+	bool imsi_detached_flag;			/* 2.7.1 */
+	bool conf_by_radio_contact_ind;			/* 2.7.4.1 */
+	bool sub_dataconf_by_hlr_ind;			/* 2.7.4.2 */
+	bool loc_conf_in_hlr_ind;			/* 2.7.4.3 */
+	bool dormant_ind;				/* 2.7.8 */
+	bool cancel_loc_rx;				/* 2.7.8A */
+	bool ms_not_reachable_flag;			/* 2.10.2 (MNRF) */
+	bool la_allowed;
+
+	int use_count;
+	time_t expire_lu;	/* FIXME: overlap with periodic_lu_timer/age_indicator */
+
+	struct osmo_fsm_inst *lu_fsm;
+	struct osmo_fsm_inst *auth_fsm;
+	struct osmo_fsm_inst *proc_arq_fsm;
+
+	bool lu_complete;
+
+	void *msc_conn_ref;
+
+	/* PS (SGSN) specific parts */
+	struct {
+		struct llist_head pdp_list;
+		uint8_t rac;
+		uint8_t sac;
+		struct gprs_mm_ctx *mmctx;
+	} ps;
+	/* CS (NITB/CSCN) specific parts */
+	struct {
+		/* pending requests */
+		bool is_paging;
+		struct llist_head requests;
+	} cs;
+};
+
+enum vlr_proc_arq_result;
+
+enum vlr_ciph {
+	VLR_CIPH_NONE, /*< A5/0, no encryption */
+	VLR_CIPH_A5_1, /*< A5/1, encryption */
+	VLR_CIPH_A5_2, /*< A5/2, deprecated export-grade encryption */
+	VLR_CIPH_A5_3, /*< A5/3, 'new secure' encryption */
+};
+
+struct vlr_ops {
+	/* encode + transmit an AUTH REQ towards the MS.
+	 * \param[in] at  auth tuple providing rand, key_seq and autn.
+	 * \param[in] send_autn  True to send AUTN, for r99 UMTS auth.
+	 */
+	int (*tx_auth_req)(void *msc_conn_ref, struct gsm_auth_tuple *at,
+			   bool send_autn);
+	/* encode + transmit an AUTH REJECT towards the MS */
+	int (*tx_auth_rej)(void *msc_conn_ref);
+
+	/* encode + transmit an IDENTITY REQUEST towards the MS */
+	int (*tx_id_req)(void *msc_conn_ref, uint8_t mi_type);
+
+	int (*tx_lu_acc)(void *msc_conn_ref, uint32_t send_tmsi);
+	int (*tx_lu_rej)(void *msc_conn_ref, uint8_t cause);
+	int (*tx_cm_serv_acc)(void *msc_conn_ref);
+	int (*tx_cm_serv_rej)(void *msc_conn_ref, enum vlr_proc_arq_result result);
+
+	int (*set_ciph_mode)(void *msc_conn_ref, enum vlr_ciph ciph_mode,
+			     bool retrieve_imeisv);
+
+	/* notify MSC/SGSN that the subscriber data in VLR has been updated */
+	void (*subscr_update)(struct vlr_subscr *vsub);
+	/* notify MSC/SGSN that the given subscriber has been associated
+	 * with this msc_conn_ref */
+	void (*subscr_assoc)(void *msc_conn_ref, struct vlr_subscr *vsub);
+};
+
+enum vlr_timer {
+	VLR_T_3250,
+	VLR_T_3260,
+	VLR_T_3270,
+	_NUM_VLR_TIMERS
+};
+
+/* An instance of the VLR codebase */
+struct vlr_instance {
+	struct llist_head subscribers;
+	struct llist_head operations;
+	struct gsup_client *gsup_client;
+	struct vlr_ops ops;
+	struct {
+		bool retrieve_imeisv;
+		bool assign_tmsi;
+		bool check_imei_rqd;
+		int auth_tuple_max_use_count;
+		bool auth_reuse_old_sets_on_error;
+		bool parq_retrieve_imsi;
+		bool is_ps;
+		uint32_t timer[_NUM_VLR_TIMERS];
+	} cfg;
+	/* A free-form pointer for use by the caller */
+	void *user_ctx;
+};
+
+extern const struct value_string vlr_ciph_names[];
+static inline const char *vlr_ciph_name(enum vlr_ciph val)
+{
+	return get_value_string(vlr_ciph_names, val);
+}
+
+/* Location Updating request */
+struct osmo_fsm_inst *
+vlr_loc_update(struct osmo_fsm_inst *parent,
+	       uint32_t parent_event_success,
+	       uint32_t parent_event_failure,
+	       void *parent_event_data,
+	       struct vlr_instance *vlr, void *msc_conn_ref,
+	       enum vlr_lu_type type, uint32_t tmsi, const char *imsi,
+	       const struct osmo_location_area_id *old_lai,
+	       const struct osmo_location_area_id *new_lai,
+	       bool authentication_required,
+	       enum vlr_ciph ciphering_required,
+	       bool is_r99, bool is_utran,
+	       bool assign_tmsi);
+
+void vlr_loc_update_conn_timeout(struct osmo_fsm_inst *fi);
+
+/* tell the VLR that the subscriber connection is gone */
+int vlr_subscr_disconnected(struct vlr_subscr *vsub);
+
+int vlr_subscr_rx_id_resp(struct vlr_subscr *vsub, const uint8_t *mi, size_t mi_len);
+int vlr_subscr_rx_auth_resp(struct vlr_subscr *vsub, bool is_r99, bool is_utran,
+			    const uint8_t *res, uint8_t res_len);
+int vlr_subscr_rx_auth_fail(struct vlr_subscr *vsub, const uint8_t *auts);
+int vlr_subscr_tx_auth_fail_rep(struct vlr_subscr *vsub);
+void vlr_subscr_rx_ciph_res(struct vlr_subscr *vsub, struct vlr_ciph_result *res);
+int vlr_subscr_rx_tmsi_reall_compl(struct vlr_subscr *vsub);
+int vlr_subscr_rx_imsi_detach(struct vlr_subscr *vsub);
+void vlr_subscr_conn_timeout(struct vlr_subscr *vsub);
+
+struct vlr_instance *vlr_alloc(void *ctx, const struct vlr_ops *ops);
+int vlr_start(const char *gsup_unit_name, struct vlr_instance *vlr,
+	      const char *gsup_server_addr_str, uint16_t gsup_server_port);
+
+/* internal use only */
+
+struct osmo_fsm_inst *sub_pres_vlr_fsm_start(struct osmo_fsm_inst *parent,
+					     struct vlr_subscr *vsub,
+					     uint32_t term_event);
+struct osmo_fsm_inst *
+upd_hlr_vlr_proc_start(struct osmo_fsm_inst *parent,
+		       struct vlr_subscr *vsub,
+		       uint32_t parent_event);
+
+struct osmo_fsm_inst *
+lu_compl_vlr_proc_start(struct osmo_fsm_inst *parent,
+			struct vlr_subscr *vsub,
+			void *msc_conn_ref,
+			uint32_t parent_event_success,
+			uint32_t parent_event_failure);
+
+
+const char *vlr_subscr_name(struct vlr_subscr *vsub);
+const char *vlr_subscr_msisdn_or_name(struct vlr_subscr *vsub);
+
+#define vlr_subscr_find_by_imsi(vlr, imsi) \
+	_vlr_subscr_find_by_imsi(vlr, imsi, __BASE_FILE__, __LINE__)
+#define vlr_subscr_find_or_create_by_imsi(vlr, imsi, created) \
+	_vlr_subscr_find_or_create_by_imsi(vlr, imsi, created, \
+					   __BASE_FILE__, __LINE__)
+
+#define vlr_subscr_find_by_tmsi(vlr, tmsi) \
+	_vlr_subscr_find_by_tmsi(vlr, tmsi, __BASE_FILE__, __LINE__)
+#define vlr_subscr_find_or_create_by_tmsi(vlr, tmsi, created) \
+	_vlr_subscr_find_or_create_by_tmsi(vlr, tmsi, created, \
+					   __BASE_FILE__, __LINE__)
+
+#define vlr_subscr_find_by_msisdn(vlr, msisdn) \
+	_vlr_subscr_find_by_msisdn(vlr, msisdn, __BASE_FILE__, __LINE__)
+
+struct vlr_subscr *_vlr_subscr_find_by_imsi(struct vlr_instance *vlr,
+					    const char *imsi,
+					    const char *file, int line);
+struct vlr_subscr *_vlr_subscr_find_or_create_by_imsi(struct vlr_instance *vlr,
+						      const char *imsi,
+						      bool *created,
+						      const char *file,
+						      int line);
+
+struct vlr_subscr *_vlr_subscr_find_by_tmsi(struct vlr_instance *vlr,
+					    uint32_t tmsi,
+					    const char *file, int line);
+struct vlr_subscr *_vlr_subscr_find_or_create_by_tmsi(struct vlr_instance *vlr,
+						      uint32_t tmsi,
+						      bool *created,
+						      const char *file,
+						      int line);
+
+struct vlr_subscr *_vlr_subscr_find_by_msisdn(struct vlr_instance *vlr,
+					      const char *msisdn,
+					      const char *file, int line);
+
+#define vlr_subscr_get(sub) _vlr_subscr_get(sub, __BASE_FILE__, __LINE__)
+#define vlr_subscr_put(sub) _vlr_subscr_put(sub, __BASE_FILE__, __LINE__)
+struct vlr_subscr *_vlr_subscr_get(struct vlr_subscr *sub, const char *file, int line);
+struct vlr_subscr *_vlr_subscr_put(struct vlr_subscr *sub, const char *file, int line);
+
+struct vlr_subscr *vlr_subscr_alloc(struct vlr_instance *vlr);
+void vlr_subscr_free(struct vlr_subscr *vsub);
+int vlr_subscr_alloc_tmsi(struct vlr_subscr *vsub);
+
+void vlr_subscr_set_imsi(struct vlr_subscr *vsub, const char *imsi);
+void vlr_subscr_set_imei(struct vlr_subscr *vsub, const char *imei);
+void vlr_subscr_set_imeisv(struct vlr_subscr *vsub, const char *imeisv);
+void vlr_subscr_set_msisdn(struct vlr_subscr *vsub, const char *msisdn);
+
+bool vlr_subscr_matches_imsi(struct vlr_subscr *vsub, const char *imsi);
+bool vlr_subscr_matches_tmsi(struct vlr_subscr *vsub, uint32_t tmsi);
+bool vlr_subscr_matches_msisdn(struct vlr_subscr *vsub, const char *msisdn);
+bool vlr_subscr_matches_imei(struct vlr_subscr *vsub, const char *imei);
+
+uint32_t vlr_timer(struct vlr_instance *vlr, uint32_t timer);
+
+int vlr_subscr_changed(struct vlr_subscr *vsub);
+int vlr_subscr_purge(struct vlr_subscr *vsub);
+void vlr_subscr_cancel(struct vlr_subscr *vsub, enum gsm48_gmm_cause cause);
+
+
+/* Process Acccess Request FSM */
+
+enum vlr_proc_arq_result {
+	VLR_PR_ARQ_RES_NONE,
+	VLR_PR_ARQ_RES_SYSTEM_FAILURE,
+	VLR_PR_ARQ_RES_ILLEGAL_SUBSCR,
+	VLR_PR_ARQ_RES_UNIDENT_SUBSCR,
+	VLR_PR_ARQ_RES_ROAMING_NOTALLOWED,
+	VLR_PR_ARQ_RES_ILLEGAL_EQUIP,
+	VLR_PR_ARQ_RES_UNKNOWN_ERROR,
+	VLR_PR_ARQ_RES_TIMEOUT,
+	VLR_PR_ARQ_RES_PASSED,
+};
+
+extern const struct value_string vlr_proc_arq_result_names[];
+static inline const char *vlr_proc_arq_result_name(enum vlr_proc_arq_result res)
+{
+	return get_value_string(vlr_proc_arq_result_names, res);
+}
+
+enum proc_arq_vlr_event {
+	PR_ARQ_E_START,
+	PR_ARQ_E_ID_IMSI,
+	PR_ARQ_E_AUTH_RES,
+	PR_ARQ_E_CIPH_RES,
+	PR_ARQ_E_UPD_LOC_RES,
+	PR_ARQ_E_TRACE_RES,
+	PR_ARQ_E_IMEI_RES,
+	PR_ARQ_E_PRES_RES,
+	PR_ARQ_E_TMSI_ACK,
+};
+
+enum vlr_parq_type {
+	VLR_PR_ARQ_T_INVALID = 0, /* to guard against unset vars */
+	VLR_PR_ARQ_T_CM_SERV_REQ,
+	VLR_PR_ARQ_T_PAGING_RESP,
+	/* FIXME: differentiate between services of 24.008 10.5.3.3 */
+};
+
+/* Process Access Request (CM SERV REQ / PAGING RESP) */
+void
+vlr_proc_acc_req(struct osmo_fsm_inst *parent,
+		 uint32_t parent_event_success,
+		 uint32_t parent_event_failure,
+		 void *parent_event_data,
+		 struct vlr_instance *vlr, void *msc_conn_ref,
+		 enum vlr_parq_type type, const uint8_t *mi_lv,
+		 const struct osmo_location_area_id *lai,
+		 bool authentication_required,
+		 enum vlr_ciph ciphering_required,
+		 bool is_r99, bool is_utran);
+
+void vlr_parq_conn_timeout(struct osmo_fsm_inst *fi);
+
+void vlr_parq_fsm_init(void);
+
+int vlr_set_ciph_mode(struct vlr_instance *vlr,
+		      struct osmo_fsm_inst *fi,
+		      void *msc_conn_ref,
+		      enum vlr_ciph ciph_mode,
+		      bool retrieve_imeisv);
+
+void log_set_filter_vlr_subscr(struct log_target *target,
+			       struct vlr_subscr *vlr_subscr);