/* API to forward upcoming NAS events, e.g. from BSSAP and RANAP, to be handled by MSC-A or MSC-I. */ /* * (C) 2019 by sysmocom s.f.m.c. GmbH * * Author: Neels Hofmeyr * * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . */ #pragma once #include #include #include #include #include #include struct msgb; struct osmo_fsm_inst; #define LOG_RAN_DEC(NAS_DEC, subsys, level, fmt, args...) \ LOGPFSMSL((NAS_DEC)? (NAS_DEC)->caller_fi : NULL, subsys, level, "RAN decode: " fmt, ## args) #define LOG_RAN_ENC(FI, subsys, level, fmt, args...) \ LOGPFSMSL(FI, subsys, level, "RAN encode: " fmt, ## args) /* These message types are named after the BSSAP procedures in nas_a.h; most are also used for RANAP procedures of * similar meaning in nas_iu.h. */ enum ran_msg_type { RAN_MSG_NONE = 0, RAN_MSG_COMPL_L3, RAN_MSG_DTAP, RAN_MSG_CLEAR_COMMAND, RAN_MSG_CLEAR_REQUEST, RAN_MSG_CLEAR_COMPLETE, RAN_MSG_CLASSMARK_REQUEST, RAN_MSG_CLASSMARK_UPDATE, RAN_MSG_CIPHER_MODE_COMMAND, RAN_MSG_CIPHER_MODE_COMPLETE, RAN_MSG_CIPHER_MODE_REJECT, RAN_MSG_COMMON_ID, RAN_MSG_ASSIGNMENT_COMMAND, RAN_MSG_ASSIGNMENT_COMPLETE, RAN_MSG_ASSIGNMENT_FAILURE, RAN_MSG_SAPI_N_REJECT, RAN_MSG_LCLS_STATUS, RAN_MSG_LCLS_BREAK_REQ, RAN_MSG_HANDOVER_COMMAND, RAN_MSG_HANDOVER_PERFORMED, RAN_MSG_HANDOVER_REQUIRED, RAN_MSG_HANDOVER_REQUIRED_REJECT, RAN_MSG_HANDOVER_REQUEST, RAN_MSG_HANDOVER_REQUEST_ACK, RAN_MSG_HANDOVER_DETECT, RAN_MSG_HANDOVER_SUCCEEDED, RAN_MSG_HANDOVER_COMPLETE, RAN_MSG_HANDOVER_FAILURE, }; extern const struct value_string ran_msg_type_names[]; static inline const char *ran_msg_type_name(enum ran_msg_type val) { return get_value_string(ran_msg_type_names, val); } struct ran_clear_command { enum gsm0808_cause gsm0808_cause; bool csfb_ind; }; struct ran_assignment_command { const struct osmo_sockaddr_str *cn_rtp; const struct gsm0808_channel_type *channel_type; enum nsap_addr_enc rab_assign_addr_enc; bool osmux_present; uint8_t osmux_cid; bool call_id_present; uint32_t call_id; struct osmo_lcls *lcls; }; struct ran_cipher_mode_command { const struct osmo_auth_vector *vec; const struct osmo_gsm48_classmark *classmark; struct { bool umts_aka; bool retrieve_imeisv; uint8_t a5_encryption_mask; /* out-argument to return the key to the caller, pass NULL if not needed. */ struct geran_encr *chosen_key; } geran; struct { uint8_t uea_encryption_mask; } utran; }; struct ran_handover_request { const char *imsi; const struct osmo_gsm48_classmark *classmark; /* A Handover Request on GERAN-A sends separate IEs for * - permitted algorithms, here composed from the a5_encryption_mask, * - the key, here taken from chosen_encryption->key iff chosen_encryption is present, * - the actually chosen algorithm ("Serving"), here taken from chosen_encryption->alg_id. */ struct { struct gsm0808_channel_type *channel_type; uint8_t a5_encryption_mask; /*! chosen_encryption->alg_id is in encoded format: * alg_id == 1 means A5/0 i.e. no encryption, alg_id == 4 means A5/3. * alg_id == 0 means no such IE was present. */ struct geran_encr *chosen_encryption; } geran; struct gsm0808_cell_id cell_id_serving; struct gsm0808_cell_id cell_id_target; enum gsm0808_cause bssap_cause; bool current_channel_type_1_present; uint8_t current_channel_type_1; enum gsm0808_permitted_speech speech_version_used; const uint8_t *old_bss_to_new_bss_info_raw; uint8_t old_bss_to_new_bss_info_raw_len; struct osmo_sockaddr_str *rtp_ran_local; struct gsm0808_speech_codec_list *codec_list_msc_preferred; bool call_id_present; uint32_t call_id; const uint8_t *global_call_reference; uint8_t global_call_reference_len; }; struct ran_handover_request_ack { const uint8_t *rr_ho_command; uint8_t rr_ho_command_len; bool chosen_channel_present; uint8_t chosen_channel; /*! chosen_encr_alg is in encoded format: * chosen_encr_alg == 1 means A5/0 i.e. no encryption, chosen_encr_alg == 4 means A5/3. * chosen_encr_alg == 0 means no such IE was present. */ uint8_t chosen_encr_alg; /* chosen_speech_version == 0 means "not present" */ enum gsm0808_permitted_speech chosen_speech_version; struct osmo_sockaddr_str remote_rtp; bool codec_present; enum mgcp_codecs codec; }; struct ran_handover_command { const uint8_t *rr_ho_command; uint8_t rr_ho_command_len; const uint8_t *new_bss_to_old_bss_info_raw; uint8_t new_bss_to_old_bss_info_raw_len; }; struct ran_handover_required { uint16_t cause; struct gsm0808_cell_id_list2 cil; bool current_channel_type_1_present; /*! See gsm0808_chosen_channel() */ uint8_t current_channel_type_1; enum gsm0808_permitted_speech speech_version_used; uint8_t *old_bss_to_new_bss_info_raw; size_t old_bss_to_new_bss_info_raw_len; }; struct ran_msg { enum ran_msg_type msg_type; /* Since different RAN implementations feed these messages, they should place here an implementation specific * string constant to name the actual message (e.g. "BSSMAP Assignment Complete" vs. "RANAP RAB Assignment * Response") */ const char *msg_name; union { struct { const struct gsm0808_cell_id *cell_id; const struct gsm0808_speech_codec_list *codec_list_bss_supported; struct msgb *msg; } compl_l3; struct msgb *dtap; struct { enum gsm0808_cause bssap_cause; #define RAN_MSG_BSSAP_CAUSE_UNSET 0xffff } clear_request; struct ran_clear_command clear_command; struct { const struct osmo_gsm48_classmark *classmark; } classmark_update; struct ran_cipher_mode_command cipher_mode_command; struct { /*! alg_id is in encoded format: * alg_id == 1 means A5/0 i.e. no encryption, alg_id == 4 means A5/3. * alg_id == 0 means no such IE was present. */ uint8_t alg_id; /*! utran integrity protection. 0..15 */ int16_t utran_integrity; /*! utran_integrity is in encoded format: * utran_integrity == -1 means no such IE was present * utran_integrity == 0 means no encryption. */ int16_t utran_encryption; const char *imeisv; const struct tlv_p_entry *l3_msg; } cipher_mode_complete; struct { enum gsm0808_cause bssap_cause; } cipher_mode_reject; struct { const char *imsi; bool last_eutran_plmn_present; struct osmo_plmn_id last_eutran_plmn; } common_id; struct { enum gsm48_reject_value cause; } cm_service_reject; struct ran_assignment_command assignment_command; struct { struct osmo_sockaddr_str remote_rtp; bool codec_present; enum mgcp_codecs codec; const struct gsm0808_speech_codec_list *codec_list_bss_supported; bool osmux_present; uint8_t osmux_cid; } assignment_complete; struct { enum gsm0808_cause bssap_cause; uint8_t rr_cause; const struct gsm0808_speech_codec_list *scl_bss_supported; } assignment_failure; struct { enum gsm0808_cause bssap_cause; uint8_t dlci; } sapi_n_reject; struct { enum gsm0808_lcls_status status; } lcls_status; struct { int todo; } lcls_break_req; struct ran_handover_required handover_required; struct gsm0808_handover_required_reject handover_required_reject; struct ran_handover_command handover_command; struct { enum gsm0808_cause cause; } handover_failure; struct ran_handover_request handover_request; struct ran_handover_request_ack handover_request_ack; }; }; /* MSC-A/I/T roles implement this to receive decoded NAS messages, upon feeding an L2 msgb to a ran_dec_l2_t matching the * RAN type implementation. */ typedef int (* ran_decode_cb_t )(struct osmo_fsm_inst *caller_fi, void *caller_data, const struct ran_msg *msg); struct ran_dec { /* caller provided osmo_fsm_inst, used both for logging from within decoding of NAS events, as well as caller's * context in decode_cb(). */ struct osmo_fsm_inst *caller_fi; void *caller_data; /* Callback receives the decoded NAS messages */ ran_decode_cb_t decode_cb; }; /* NAS decoders (BSSAP/RANAP) implement this to turn a msgb into a struct ran_msg. * An implementation typically calls ran_decoded() when done decoding. * NAS decoding is modeled with a callback instead of a plain decoding, because some L2 messages by design contain more * than one NAS event, e.g. Ciphering Mode Complete may include another L3 message for Identity Response, and LCLS * Information messages can contain Status and Break Req events. */ typedef int (* ran_dec_l2_t )(struct ran_dec *ran_dec, struct msgb *l2); int ran_decoded(struct ran_dec *ran_dec, struct ran_msg *msg); /* An MSC-A/I/T role that receives NAS events containing DTAP buffers may use this to detect DTAP duplicates as in TS * 24.007 11.2.3.2 Message Type Octet / Duplicate Detection */ bool ran_dec_dtap_undup_is_duplicate(struct osmo_fsm_inst *log_fi, uint8_t *n_sd_next, bool is_r99, struct msgb *l3); /* Implemented by individual RAN implementations, see ran_a_encode() and ran_iu_encode(). */ typedef struct msgb *(* ran_encode_t )(struct osmo_fsm_inst *caller_fi, const struct ran_msg *ran_enc_msg);