In this patch we're sending an ICMPv6 message to a peer to immediately inform it that making a connection is not possible. In case of TCP connections, without this change, the peer will be waiting until a connection timeout is exceeded. Signed-off-by: Piotr Sawicki <p.sawicki2(a)partner.samsung.com&gt; --- security/smack/smack_lsm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index c2282ac..efa81bc 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -28,6 +28,7 @@ #include <linux/tcp.h> #include <linux/udp.h> #include <linux/dccp.h> +#include <linux/icmpv6.h> #include <linux/slab.h> #include <linux/mutex.h> #include <linux/pipe_fs_i.h> @@ -4010,6 +4011,9 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) #ifdef SMACK_IPV6_PORT_LABELING rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING); #endif /* SMACK_IPV6_PORT_LABELING */ + if (rc != 0) + icmpv6_send(skb, ICMPV6_DEST_UNREACH, + ICMPV6_ADM_PROHIBITED, 0); break; #endif /* CONFIG_IPV6 */ } -- 2.7.4