Commit bc43a3c8 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

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: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarBrian Vazquez <brianvv@google.com>
Link: https://patch.msgid.link/20241010174817.1543642-3-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 78e2baf3

include/net/sock.h

+10 −0
Original line number Diff line number Diff line
@@ -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);

net/sched/sch_fq.c

+2 −1
Original line number Diff line number Diff line
@@ -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