Here are the data structures with brief descriptions:

Cdl_rel_req_param	For DL-REL.req
Cl2downstate
Clapd_cr_ent
Clapd_datalink	LAPD datalink
C[struct].cr
Clapd_history
Clapd_msg_ctx	LAPD message context
Cmdl_error_ind_param	For MDL-ERROR.ind
Cosmo_dlsap_prim	Primitive header for LAPD DL-SAP primitives
C[union].u
Cosmo_i460_schan_desc	Description of a sub-channel; passed by caller
C[struct].demux
C[struct].mux
Cosmo_i460_subchan
Cosmo_i460_subchan_demux
Cosmo_i460_subchan_mux
Cosmo_i460_timeslot
Cosmo_v110_decoded_frame	'decoded' representation of a single V.110 frame
Cosmo_v110_sync_ra1
Cosmo_v110_ta
Cosmo_v110_ta_cfg	Configuration for a V.110 TA instance
C[struct].flow_ctrl	Flow control configuration
Cv110_ta_state
C[struct].tx
C[struct].rx