- bool (*send_packet)(struct tnl *tnl, const char *buf, int len);
- bool (*send_meta)(struct tnl *tnl, const char *buf, int len);
+ bool (*send_packet)(struct tnl *tnl, const void *buf, int len);
+ bool (*send_meta)(struct tnl *tnl, const void *buf, int len);