From 669da7a71890b2b2a31a7e9571c0fdf1123e26ef Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 15 Apr 2022 17:10:43 -0700 Subject: tcp: add drop reasons to tcp_rcv_state_process() Add basic support for drop reasons in tcp_rcv_state_process() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index f95a8368981d..85fae79c894d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6413,21 +6413,26 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) struct request_sock *req; int queued = 0; bool acceptable; + SKB_DR(reason); switch (sk->sk_state) { case TCP_CLOSE: + SKB_DR_SET(reason, TCP_CLOSE); goto discard; case TCP_LISTEN: if (th->ack) return 1; - if (th->rst) + if (th->rst) { + SKB_DR_SET(reason, TCP_RESET); goto discard; - + } if (th->syn) { - if (th->fin) + if (th->fin) { + SKB_DR_SET(reason, TCP_FLAGS); goto discard; + } /* It is possible that we process SYN packets from backlog, * so we need to make sure to disable BH and RCU right there. */ @@ -6442,6 +6447,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) consume_skb(skb); return 0; } + SKB_DR_SET(reason, TCP_FLAGS); goto discard; case TCP_SYN_SENT: @@ -6468,13 +6474,16 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) WARN_ON_ONCE(sk->sk_state != TCP_SYN_RECV && sk->sk_state != TCP_FIN_WAIT1); - if (!tcp_check_req(sk, skb, req, true, &req_stolen)) + if (!tcp_check_req(sk, skb, req, true, &req_stolen)) { + SKB_DR_SET(reason, TCP_FASTOPEN); goto discard; + } } - if (!th->ack && !th->rst && !th->syn) + if (!th->ack && !th->rst && !th->syn) { + SKB_DR_SET(reason, TCP_FLAGS); goto discard; - + } if (!tcp_validate_incoming(sk, skb, th, 0)) return 0; @@ -6487,6 +6496,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) if (sk->sk_state == TCP_SYN_RECV) return 1; /* send one RST */ tcp_send_challenge_ack(sk); + SKB_DR_SET(reason, TCP_OLD_ACK); goto discard; } switch (sk->sk_state) { @@ -6647,7 +6657,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) if (!queued) { discard: - tcp_drop(sk, skb); + tcp_drop_reason(sk, skb, reason); } return 0; -- cgit