PF_TO_PPP
ppp = PF_TO_PPP(pf);
ppp_destroy_interface(PF_TO_PPP(pf));
struct ppp *ppp = PF_TO_PPP(pf);
ppp_xmit_process(PF_TO_PPP(pf), skb);
struct ppp *ppp = PF_TO_PPP(pf);
ppp = PF_TO_PPP(pf);
struct ppp *ppp = PF_TO_PPP(pf);