add LAPDm code from osmocom-bb into libosmocore

1 files changed, 186 insertions, 0 deletions

diff --git a/include/osmocom/gsm/lapdm.h b/include/osmocom/gsm/lapdm.h
new file mode 100644
index 00000000..2e78aeee
--- /dev/null
+++ b/include/osmocom/gsm/lapdm.h
@@ -0,0 +1,186 @@
+#ifndef _OSMOCOM_LAPDM_H
+#define _OSMOCOM_LAPDM_H
+
+#include <stdint.h>
+
+#include <osmocom/core/timer.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/gsm/prim.h>
+
+/* primitive related sutff */
+
+enum osmo_ph_prim {
+	PRIM_PH_DATA,		/* PH-DATA */
+	PRIM_PH_RACH,		/* PH-RANDOM_ACCESS */
+	PRIM_PH_CONN,		/* PH-CONNECT */
+	PRIM_PH_EMPTY_FRAME,	/* PH-EMPTY_FRAME */
+	PRIM_PH_RTS,		/* PH-RTS */
+};
+
+/* for PH-RANDOM_ACCESS.req */
+struct ph_rach_req_param {
+	uint8_t ra;
+	uint8_t ta;
+	uint8_t tx_power;
+	uint8_t is_combined_ccch;
+	uint16_t offset;
+};
+
+/* for PH-RANDOM_ACCESS.ind */
+struct ph_rach_ind_param {
+	uint8_t ra;
+	uint8_t acc_delay;
+	uint32_t fn;
+};
+
+/* for PH-[UNIT]DATA.{req,ind} */
+struct ph_data_param {
+	uint8_t link_id;
+	uint8_t chan_nr;
+};
+
+struct ph_conn_ind_param {
+	uint32_t fn;
+};
+
+struct osmo_phsap_prim {
+	struct osmo_prim_hdr oph;
+	union {
+		struct ph_data_param data;
+		struct ph_rach_req_param rach_req;
+		struct ph_rach_ind_param rach_ind;
+		struct ph_conn_ind_param conn_ind;
+	} u;
+};
+
+enum lapdm_mode {
+	LAPDM_MODE_MS,
+	LAPDM_MODE_BTS,
+};
+
+enum lapdm_state {
+	LAPDm_STATE_NULL = 0,
+	LAPDm_STATE_IDLE,
+	LAPDm_STATE_SABM_SENT,
+	LAPDm_STATE_MF_EST,
+	LAPDm_STATE_TIMER_RECOV,
+	LAPDm_STATE_DISC_SENT,
+};
+
+struct lapdm_entity;
+
+struct lapdm_msg_ctx {
+	struct lapdm_datalink *dl;
+	int lapdm_fmt;
+	uint8_t n201;
+	uint8_t chan_nr;
+	uint8_t link_id;
+	uint8_t addr;
+	uint8_t ctrl;
+	uint8_t ta_ind;
+	uint8_t tx_power_ind;
+};
+
+/* TS 04.06 / Section 3.5.2 */
+struct lapdm_datalink {
+	uint8_t V_send;	/* seq nr of next I frame to be transmitted */
+	uint8_t V_ack;	/* last frame ACKed by peer */
+	uint8_t N_send;	/* ? set to V_send at Tx time*/
+	uint8_t V_recv;	/* seq nr of next I frame expected to be received */
+	uint8_t N_recv;	/* expected send seq nr of the next received I frame */
+	uint32_t state;
+	int seq_err_cond; /* condition of sequence error */
+	uint8_t own_busy, peer_busy;
+	struct osmo_timer_list t200;
+	uint8_t retrans_ctr;
+	struct llist_head send_queue; /* frames from L3 */
+	struct msgb *send_buffer; /* current frame transmitting */
+	int send_out; /* how much was sent from send_buffer */
+	uint8_t tx_hist[8][200]; /* tx history buffer */
+	int tx_length[8]; /* length in history buffer */
+	struct llist_head tx_queue; /* frames to L1 */
+	struct lapdm_msg_ctx mctx; /* context of established connection */
+	struct msgb *rcv_buffer; /* buffer to assemble the received message */
+
+	struct lapdm_entity *entity;
+};
+
+enum lapdm_dl_sapi {
+	DL_SAPI0	= 0,
+	DL_SAPI3	= 1,
+	_NR_DL_SAPI
+};
+
+typedef int (*lapdm_cb_t)(struct msgb *msg, struct lapdm_entity *le, void *ctx);
+
+struct lapdm_cr_ent {
+	uint8_t cmd;
+	uint8_t resp;
+};
+
+#define LAPDM_ENT_F_EMPTY_FRAME		0x0001
+#define LAPDM_ENT_F_POLLING_ONLY	0x0002
+
+/* register message handler for messages that are sent from L2->L3 */
+struct lapdm_entity {
+	struct lapdm_datalink datalink[_NR_DL_SAPI];
+	int last_tx_dequeue; /* last entity that was dequeued */
+	int tx_pending; /* currently a pending frame not confirmed by L1 */
+	enum lapdm_mode mode; /* are we in BTS mode or MS mode */
+	unsigned int flags;
+
+	struct {
+		/* filled-in once we set the lapdm_mode above */
+		struct lapdm_cr_ent loc2rem;
+		struct lapdm_cr_ent rem2loc;
+	} cr;
+
+	void *l1_ctx;	/* context for layer1 instance */
+	void *l3_ctx;	/* context for layer3 instance */
+
+	osmo_prim_cb l1_prim_cb;
+	lapdm_cb_t l3_cb;	/* callback for sending stuff to L3 */
+
+	struct lapdm_channel *lapdm_ch;
+};
+
+/* the two lapdm_entities that form a GSM logical channel (ACCH + DCCH) */
+struct lapdm_channel {
+	struct llist_head list;
+	char *name;
+	struct lapdm_entity lapdm_acch;
+	struct lapdm_entity lapdm_dcch;
+};
+
+const char *get_rsl_name(int value);
+extern const char *lapdm_state_names[];
+
+/* initialize a LAPDm entity */
+void lapdm_entity_init(struct lapdm_entity *le, enum lapdm_mode mode);
+void lapdm_channel_init(struct lapdm_channel *lc, enum lapdm_mode mode);
+
+/* deinitialize a LAPDm entity */
+void lapdm_entity_exit(struct lapdm_entity *le);
+void lapdm_channel_exit(struct lapdm_channel *lc);
+
+/* input into layer2 (from layer 1) */
+int lapdm_phsap_up(struct osmo_prim_hdr *oph, struct lapdm_entity *le);
+
+/* input into layer2 (from layer 3) */
+int lapdm_rslms_recvmsg(struct msgb *msg, struct lapdm_channel *lc);
+
+void lapdm_channel_set_l3(struct lapdm_channel *lc, lapdm_cb_t cb, void *ctx);
+void lapdm_channel_set_l1(struct lapdm_channel *lc, osmo_prim_cb cb, void *ctx);
+
+int lapdm_entity_set_mode(struct lapdm_entity *le, enum lapdm_mode mode);
+int lapdm_channel_set_mode(struct lapdm_channel *lc, enum lapdm_mode mode);
+
+void lapdm_entity_reset(struct lapdm_entity *le);
+void lapdm_channel_reset(struct lapdm_channel *lc);
+
+void lapdm_entity_set_flags(struct lapdm_entity *le, unsigned int flags);
+void lapdm_channel_set_flags(struct lapdm_channel *lc, unsigned int flags);
+
+int lapdm_phsap_dequeue_prim(struct lapdm_entity *le, struct osmo_phsap_prim *pp);
+
+#endif /* _OSMOCOM_LAPDM_H */