@@ -357,6 +357,7 @@ enum skb_drop_reason {
* backlog (see
* LINUX_MIB_TCPBACKLOGDROP)
*/
+ SKB_DROP_REASON_TCP_FLAGS, /* TCP flags invalid */
SKB_DROP_REASON_MAX,
};
@@ -32,6 +32,7 @@
TCP_MD5UNEXPECTED) \
EM(SKB_DROP_REASON_TCP_MD5FAILURE, TCP_MD5FAILURE) \
EM(SKB_DROP_REASON_SOCKET_BACKLOG, SOCKET_BACKLOG) \
+ EM(SKB_DROP_REASON_TCP_FLAGS, TCP_FLAGS) \
EMe(SKB_DROP_REASON_MAX, MAX)
#undef EM
@@ -5787,6 +5787,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
*/
void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
{
+ enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
const struct tcphdr *th = (const struct tcphdr *)skb->data;
struct tcp_sock *tp = tcp_sk(sk);
unsigned int len = skb->len;
@@ -5875,6 +5876,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
tp->rcv_rtt_last_tsecr = tp->rx_opt.rcv_tsecr;
return;
} else { /* Header too small */
+ reason = SKB_DROP_REASON_PKT_TOO_SMALL;
TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
goto discard;
}
@@ -5930,8 +5932,10 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
if (len < (th->doff << 2) || tcp_checksum_complete(skb))
goto csum_error;
- if (!th->ack && !th->rst && !th->syn)
+ if (!th->ack && !th->rst && !th->syn) {
+ reason = SKB_DROP_REASON_TCP_FLAGS;
goto discard;
+ }
/*
* Standard slow path.
@@ -5957,12 +5961,13 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
return;
csum_error:
+ reason = SKB_DROP_REASON_TCP_CSUM;
trace_tcp_bad_csum(skb);
TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
discard:
- tcp_drop(sk, skb);
+ tcp_drop_reason(sk, skb, reason);
}
EXPORT_SYMBOL(tcp_rcv_established);