Commit 2a968ef6 authored by Menglong Dong's avatar Menglong Dong Committed by David S. Miller
Browse files

net: tcp: use tcp_drop_reason() for tcp_rcv_established() 



Replace tcp_drop() used in tcp_rcv_established() with tcp_drop_reason().
Following drop reasons are added:

SKB_DROP_REASON_TCP_FLAGS

Reviewed-by: default avatarMengen Sun <mengensun@tencent.com>
Reviewed-by: default avatarHao Peng <flyingpeng@tencent.com>
Signed-off-by: default avatarMenglong Dong <imagedong@tencent.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8eba65fa

include/linux/skbuff.h

+1 −0
Original line number Diff line number Diff line
@@ -362,6 +362,7 @@ enum skb_drop_reason { 
					 * backlog (see

					 * LINUX_MIB_TCPBACKLOGDROP)

					 */

	SKB_DROP_REASON_TCP_FLAGS,	/* TCP flags invalid */

	SKB_DROP_REASON_MAX,

};

include/trace/events/skb.h

+1 −0
Original line number Diff line number Diff line
@@ -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

net/ipv4/tcp_input.c

+7 −2
Original line number Diff line number Diff line
@@ -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);