static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	int err;
	struct sk_security_struct *sksec = sk->sk_security;
	u16 family = sk->sk_family;
	u32 sk_sid = sksec->sid;
	struct common_audit_data ad;
	struct lsm_network_audit net = {0,};
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;

	if (family != PF_INET && family != PF_INET6)
		return 0;

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;

	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_sock_rcv_skb_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
	if (!selinux_policycap_netpeer)
		return selinux_sock_rcv_skb_compat(sk, skb, family);

	secmark_active = selinux_secmark_enabled();
	peerlbl_active = selinux_peerlbl_enabled();
	if (!secmark_active && !peerlbl_active)
		return 0;

	ad.type = LSM_AUDIT_DATA_NET;
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
	if (err)
		return err;

	if (peerlbl_active) {
		u32 peer_sid;

		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
		if (err)
			return err;
		err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
					       peer_sid, &ad);
		if (err) {
			selinux_netlbl_err(skb, err, 0);
			return err;
		}
		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
				   PEER__RECV, &ad);
		if (err) {
			selinux_netlbl_err(skb, err, 0);
			return err;
		}
	}

	if (secmark_active) {
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
				   PACKET__RECV, &ad);
		if (err)
			return err;
	}

	return err;
}
Unknown