puzzled

+/*+  oslec.h+  David Rowe+  7 Feb 2007++  Interface for OSLEC module.+*/++#ifndef __OSLEC__+#define __OSLEC__++#define ZAPTEL_ECHO_CANCELLER "OSLEC"+static inline void echo_can_identify(char *buf, size_t len)+{+strncpy(buf, ZAPTEL_ECHO_CANCELLER, len);+};++struct echo_can_state {+  void *ec;+};++struct echo_can_state *oslec_echo_can_create(int len, int adaption_mode);+void oslec_echo_can_free(struct echo_can_state *ec);+short oslec_echo_can_update(struct echo_can_state *ec, short iref, short isig);+int oslec_echo_can_traintap(struct echo_can_state *ec, int pos, short val);+static inline void echo_can_init(void) {}+static inline void echo_can_shutdown(void) {}+short oslec_hpf_tx(struct echo_can_state *ec, short txlin);++#endif+