get_saddr
void (*get_saddr) (struct sctp_sock *sk,
int (*get_saddr)(xfrm_address_t *saddr,
fl4.saddr = get_saddr(iph->saddr);
fl4.saddr = get_saddr(iph->daddr);
.get_saddr = xfrm4_get_saddr,
.get_saddr = xfrm6_get_saddr,
.get_saddr = sctp_v6_get_saddr,
.get_saddr = sctp_v4_get_saddr,
af->get_saddr(opt, transport, &transport->fl);
err = afinfo->get_saddr(saddr, params);