Symbol: PF_NL_PROTO
lib/libpfctl/libpfctl.c
2897
snl_add_msg_attr_u8(&nw, PF_NL_PROTO, k->proto);
sys/netpfil/pf/pf_nl.c
1304
{ .type = PF_NL_PROTO, .off = _OUT(proto), .cb = nlattr_get_uint8 },