From bc43a3c83cad46a27d6e3bf869acdd926bbe79ad Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 10 Oct 2024 17:48:14 +0000 Subject: [PATCH] net_sched: sch_fq: prepare for TIME_WAIT sockets TCP stack is not attaching skb to TIME_WAIT sockets yet, but we would like to allow this in the future. Add sk_listener_or_tw() helper to detect the three states that FQ needs to take care. Like NEW_SYN_RECV, TIME_WAIT are not full sockets and do not contain sk->sk_pacing_status, sk->sk_pacing_rate. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Reviewed-by: Brian Vazquez Link: https://patch.msgid.link/20241010174817.1543642-3-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/net/sock.h | 10 ++++++++++ net/sched/sch_fq.c | 3 ++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/include/net/sock.h b/include/net/sock.h index 6da420ab1ee1..2f200d91ef11 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2802,6 +2802,16 @@ static inline bool sk_listener(const struct sock *sk) return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV); } +/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV or TIME_WAIT + * TCP SYNACK messages can be attached to LISTEN or NEW_SYN_RECV (depending on SYNCOOKIE) + * TCP RST and ACK can be attached to TIME_WAIT. + */ +static inline bool sk_listener_or_tw(const struct sock *sk) +{ + return (1 << READ_ONCE(sk->sk_state)) & + (TCPF_LISTEN | TCPF_NEW_SYN_RECV | TCPF_TIME_WAIT); +} + void sock_enable_timestamp(struct sock *sk, enum sock_flags flag); int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level, int type); diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c index aeabf45c9200..a97638bef6da 100644 --- a/net/sched/sch_fq.c +++ b/net/sched/sch_fq.c @@ -362,8 +362,9 @@ static struct fq_flow *fq_classify(struct Qdisc *sch, struct sk_buff *skb, * 3) We do not want to rate limit them (eg SYNFLOOD attack), * especially if the listener set SO_MAX_PACING_RATE * 4) We pretend they are orphaned + * TCP can also associate TIME_WAIT sockets with RST or ACK packets. */ - if (!sk || sk_listener(sk)) { + if (!sk || sk_listener_or_tw(sk)) { unsigned long hash = skb_get_hash(skb) & q->orphan_mask; /* By forcing low order bit to 1, we make sure to not