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Diffstat (limited to 'include/openbsc/gprs_llc.h')
-rw-r--r-- | include/openbsc/gprs_llc.h | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/include/openbsc/gprs_llc.h b/include/openbsc/gprs_llc.h new file mode 100644 index 000000000..8bc226781 --- /dev/null +++ b/include/openbsc/gprs_llc.h @@ -0,0 +1,284 @@ +#ifndef _GPRS_LLC_H +#define _GPRS_LLC_H + +#include <stdint.h> +#include <stdbool.h> +#include <openbsc/gprs_sgsn.h> +#include <openbsc/gprs_llc_xid.h> + +/* Section 4.7 LLC Layer Structure */ +enum gprs_llc_sapi { + GPRS_SAPI_GMM = 1, + GPRS_SAPI_TOM2 = 2, + GPRS_SAPI_SNDCP3 = 3, + GPRS_SAPI_SNDCP5 = 5, + GPRS_SAPI_SMS = 7, + GPRS_SAPI_TOM8 = 8, + GPRS_SAPI_SNDCP9 = 9, + GPRS_SAPI_SNDCP11 = 11, +}; + +/* Section 6.4 Commands and Responses */ +enum gprs_llc_u_cmd { + GPRS_LLC_U_DM_RESP = 0x01, + GPRS_LLC_U_DISC_CMD = 0x04, + GPRS_LLC_U_UA_RESP = 0x06, + GPRS_LLC_U_SABM_CMD = 0x07, + GPRS_LLC_U_FRMR_RESP = 0x08, + GPRS_LLC_U_XID = 0x0b, + GPRS_LLC_U_NULL_CMD = 0x00, +}; + +/* Section 6.4.1.6 / Table 6 */ +enum gprs_llc_xid_type { + GPRS_LLC_XID_T_VERSION = 0, + GPRS_LLC_XID_T_IOV_UI = 1, + GPRS_LLC_XID_T_IOV_I = 2, + GPRS_LLC_XID_T_T200 = 3, + GPRS_LLC_XID_T_N200 = 4, + GPRS_LLC_XID_T_N201_U = 5, + GPRS_LLC_XID_T_N201_I = 6, + GPRS_LLC_XID_T_mD = 7, + GPRS_LLC_XID_T_mU = 8, + GPRS_LLC_XID_T_kD = 9, + GPRS_LLC_XID_T_kU = 10, + GPRS_LLC_XID_T_L3_PAR = 11, + GPRS_LLC_XID_T_RESET = 12, +}; + +extern const struct value_string gprs_llc_xid_type_names[]; + +/* TS 04.64 Section 7.1.2 Table 7: LLC layer primitives (GMM/SNDCP/SMS/TOM) */ +/* TS 04.65 Section 5.1.2 Table 2: Service primitives used by SNDCP */ +enum gprs_llc_primitive { + /* GMM <-> LLME */ + LLGMM_ASSIGN_REQ, /* GMM tells us new TLLI: TLLI old, TLLI new, Kc, CiphAlg */ + LLGMM_RESET_REQ, /* GMM tells us to perform XID negotiation: TLLI */ + LLGMM_RESET_CNF, /* LLC informs GMM that XID has completed: TLLI */ + LLGMM_SUSPEND_REQ, /* GMM tells us MS has suspended: TLLI, Page */ + LLGMM_RESUME_REQ, /* GMM tells us MS has resumed: TLLI */ + LLGMM_PAGE_IND, /* LLC asks GMM to page MS: TLLI */ + LLGMM_IOV_REQ, /* GMM tells us to perform XID: TLLI */ + LLGMM_STATUS_IND, /* LLC informs GMM about error: TLLI, Cause */ + /* LLE <-> (GMM/SNDCP/SMS/TOM) */ + LL_RESET_IND, /* TLLI */ + LL_ESTABLISH_REQ, /* TLLI, XID Req */ + LL_ESTABLISH_IND, /* TLLI, XID Req, N201-I, N201-U */ + LL_ESTABLISH_RESP, /* TLLI, XID Negotiated */ + LL_ESTABLISH_CONF, /* TLLI, XID Neg, N201-i, N201-U */ + LL_RELEASE_REQ, /* TLLI, Local */ + LL_RELEASE_IND, /* TLLI, Cause */ + LL_RELEASE_CONF, /* TLLI */ + LL_XID_REQ, /* TLLI, XID Requested */ + LL_XID_IND, /* TLLI, XID Req, N201-I, N201-U */ + LL_XID_RESP, /* TLLI, XID Negotiated */ + LL_XID_CONF, /* TLLI, XID Neg, N201-I, N201-U */ + LL_DATA_REQ, /* TLLI, SN-PDU, Ref, QoS, Radio Prio, Ciph */ + LL_DATA_IND, /* TLLI, SN-PDU */ + LL_DATA_CONF, /* TLLI, Ref */ + LL_UNITDATA_REQ, /* TLLI, SN-PDU, Ref, QoS, Radio Prio, Ciph */ + LL_UNITDATA_IND, /* TLLI, SN-PDU */ + LL_STATUS_IND, /* TLLI, Cause */ +}; + +/* Section 4.5.2 Logical Link States + Annex C.2 */ +enum gprs_llc_lle_state { + GPRS_LLES_UNASSIGNED = 1, /* No TLLI yet */ + GPRS_LLES_ASSIGNED_ADM = 2, /* TLLI assigned */ + GPRS_LLES_LOCAL_EST = 3, /* Local Establishment */ + GPRS_LLES_REMOTE_EST = 4, /* Remote Establishment */ + GPRS_LLES_ABM = 5, + GPRS_LLES_LOCAL_REL = 6, /* Local Release */ + GPRS_LLES_TIMER_REC = 7, /* Timer Recovery */ +}; + +enum gprs_llc_llme_state { + GPRS_LLMS_UNASSIGNED = 1, /* No TLLI yet */ + GPRS_LLMS_ASSIGNED = 2, /* TLLI assigned */ +}; + +/* Section 8.9.9 LLC layer parameter default values */ +struct gprs_llc_params { + uint16_t iov_i_exp; + uint16_t t200_201; + uint16_t n200; + uint16_t n201_u; + uint16_t n201_i; + uint16_t mD; + uint16_t mU; + uint16_t kD; + uint16_t kU; +}; + +/* Section 4.7.1: Logical Link Entity: One per DLCI (TLLI + SAPI) */ +struct gprs_llc_lle { + struct llist_head list; + + uint32_t sapi; + + struct gprs_llc_llme *llme; + + enum gprs_llc_lle_state state; + + struct osmo_timer_list t200; + struct osmo_timer_list t201; /* wait for acknowledgement */ + + uint16_t v_sent; + uint16_t v_ack; + uint16_t v_recv; + + uint16_t vu_send; + uint16_t vu_recv; + + /* non-standard LLC state */ + uint16_t vu_recv_last; + uint16_t vu_recv_duplicates; + + /* Overflow Counter for ABM */ + uint32_t oc_i_send; + uint32_t oc_i_recv; + + /* Overflow Counter for unconfirmed transfer */ + uint32_t oc_ui_send; + uint32_t oc_ui_recv; + + unsigned int retrans_ctr; + + struct gprs_llc_params params; +}; + +#define NUM_SAPIS 16 + +struct gprs_llc_llme { + struct llist_head list; + + enum gprs_llc_llme_state state; + + uint32_t tlli; + uint32_t old_tlli; + + /* Crypto parameters */ + enum gprs_ciph_algo algo; + uint8_t kc[16]; + uint8_t cksn; + /* 3GPP TS 44.064 ยง 8.9.2: */ + uint32_t iov_ui; + + /* over which BSSGP BTS ctx do we need to transmit */ + uint16_t bvci; + uint16_t nsei; + struct gprs_llc_lle lle[NUM_SAPIS]; + + /* Copy of the XID fields we have sent with the last + * network originated XID-Request. Since the phone + * may strip the optional fields in the confirmation + * we need to remeber those fields in order to be + * able to create the compression entity. */ + struct llist_head *xid; + + /* Compression entities */ + struct { + /* In these two list_heads we will store the + * data and protocol compression entities, + * together with their compression states */ + struct llist_head *proto; + struct llist_head *data; + } comp; + + /* Internal management */ + uint32_t age_timestamp; +}; + +#define GPRS_LLME_RESET_AGE (0) + +extern struct llist_head gprs_llc_llmes; + +/* LLC low level types */ + +enum gprs_llc_cmd { + GPRS_LLC_NULL, + GPRS_LLC_RR, + GPRS_LLC_ACK, + GPRS_LLC_RNR, + GPRS_LLC_SACK, + GPRS_LLC_DM, + GPRS_LLC_DISC, + GPRS_LLC_UA, + GPRS_LLC_SABM, + GPRS_LLC_FRMR, + GPRS_LLC_XID, + GPRS_LLC_UI, +}; + +struct gprs_llc_hdr_parsed { + uint8_t sapi; + uint8_t is_cmd:1, + ack_req:1, + is_encrypted:1; + uint32_t seq_rx; + uint32_t seq_tx; + uint32_t fcs; + uint32_t fcs_calc; + uint8_t *data; + uint16_t data_len; + uint16_t crc_length; + enum gprs_llc_cmd cmd; +}; + + +/* BSSGP-UL-UNITDATA.ind */ +int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv); + +/* LL-UNITDATA.req */ +int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command, + struct sgsn_mm_ctx *mmctx, bool encryptable); + +/* Chapter 7.2.1.2 LLGMM-RESET.req */ +int gprs_llgmm_reset(struct gprs_llc_llme *llme); +int gprs_llgmm_reset_oldmsg(struct msgb* oldmsg, uint8_t sapi, + struct gprs_llc_llme *llme); + +/* Set of LL-XID negotiation (See also: TS 101 351, Section 7.2.2.4) */ +int gprs_ll_xid_req(struct gprs_llc_lle *lle, + struct gprs_llc_xid_field *l3_xid_field); + +/* 04.64 Chapter 7.2.1.1 LLGMM-ASSIGN */ +int gprs_llgmm_assign(struct gprs_llc_llme *llme, + uint32_t old_tlli, uint32_t new_tlli); +int gprs_llgmm_unassign(struct gprs_llc_llme *llme); + +int gprs_llc_init(const char *cipher_plugin_path); +int gprs_llc_vty_init(void); + +/** + * \short Check if N(U) should be considered a retransmit + * + * Implements the range check as of GSM 04.64 8.4.2 + * Receipt of unacknowledged information. + * + * @returns Returns 1 if (V(UR)-32) <= N(U) < V(UR) + * @param nu N(U) unconfirmed sequence number of the UI frame + * @param vur V(UR) unconfirmend received state variable + */ +static inline int gprs_llc_is_retransmit(uint16_t nu, uint16_t vur) +{ + int delta = (vur - nu) & 0x1ff; + return 0 < delta && delta < 32; +} + +/* LLC low level functions */ +void gprs_llme_copy_key(struct sgsn_mm_ctx *mm, struct gprs_llc_llme *llme); + +/* parse a GPRS LLC header, also check for invalid frames */ +int gprs_llc_hdr_parse(struct gprs_llc_hdr_parsed *ghp, + uint8_t *llc_hdr, int len); +void gprs_llc_hdr_dump(struct gprs_llc_hdr_parsed *gph, struct gprs_llc_lle *lle); +int gprs_llc_fcs(uint8_t *data, unsigned int len); + + +/* LLME handling routines */ +struct llist_head *gprs_llme_list(void); +struct gprs_llc_lle *gprs_lle_get_or_create(const uint32_t tlli, uint8_t sapi); + + +#endif |