From: Eric Dumazet <eduma...@google.com>
Add basic support for drop reasons in tcp_rcv_state_process()
Signed-off-by: Eric Dumazet <eduma...@google.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Acked-by: Nikolay Borisov <nbori...@suse.com>
Signed-off-by: Nikolay Borisov <nikolay.bori...@virtuozzo.com>
---
include/linux/skbuff.h | 3 +++
include/trace/events/skb.h | 7 +++++--
net/ipv4/tcp_input.c | 22 +++++++++++++++++-----
3 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index dc38a214eee4..217dce9f6f0f 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -385,6 +385,9 @@ enum skb_drop_reason {
SKB_DROP_REASON_TCP_INVALID_SEQUENCE, /* Not acceptable SEQ field */
SKB_DROP_REASON_TCP_RESET, /* Invalid RST packet */
SKB_DROP_REASON_TCP_INVALID_SYN, /* Incoming packet has unexpected SYN
flag */
+ SKB_DROP_REASON_TCP_CLOSE, /* TCP socket in CLOSE state */
+ SKB_DROP_REASON_TCP_FASTOPEN, /* dropped by FASTOPEN request socket */
+ SKB_DROP_REASON_TCP_OLD_ACK, /* TCP ACK is old, but in window */
SKB_DROP_REASON_IP_OUTNOROUTES, /* route lookup failed */
SKB_DROP_REASON_BPF_CGROUP_EGRESS, /* dropped by
* BPF_PROG_TYPE_CGROUP_SKB
diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
index bb704d7ea8c9..a726a70f7596 100644
--- a/include/trace/events/skb.h
+++ b/include/trace/events/skb.h
@@ -40,8 +40,11 @@
EM(SKB_DROP_REASON_TCP_RFC7323_PAWS, TCP_RFC7323_PAWS) \
EM(SKB_DROP_REASON_TCP_INVALID_SEQUENCE, \
TCP_INVALID_SEQUENCE) \
- EM(SKB_DROP_REASON_TCP_RESET, TCP_RESET) \
- EM(SKB_DROP_REASON_TCP_INVALID_SYN, TCP_INVALID_SYN) \
+ EM(SKB_DROP_REASON_TCP_RESET, TCP_RESET) \
+ EM(SKB_DROP_REASON_TCP_INVALID_SYN, TCP_INVALID_SYN) \
+ EM(SKB_DROP_REASON_TCP_CLOSE, TCP_CLOSE) \
+ EM(SKB_DROP_REASON_TCP_FASTOPEN, TCP_FASTOPEN) \
+ EM(SKB_DROP_REASON_TCP_OLD_ACK, TCP_OLD_ACK) \
EM(SKB_DROP_REASON_IP_OUTNOROUTES, IP_OUTNOROUTES) \
EM(SKB_DROP_REASON_BPF_CGROUP_EGRESS, \
BPF_CGROUP_EGRESS) \
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 9db35e8fe894..fad3792f71f4 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6374,21 +6374,27 @@ 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.
*/
@@ -6403,6 +6409,7 @@ 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:
@@ -6429,12 +6436,16 @@ 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;
@@ -6448,6 +6459,7 @@ 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);
+ SKB_DR_SET(reason, TCP_OLD_ACK);
goto discard;
}
switch (sk->sk_state) {
@@ -6608,7 +6620,7 @@ 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;
}
--
2.34.1
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