Commit f6c0f5d2 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: honor SO_PRIORITY in TIME_WAIT state 



ctl packets sent on behalf of TIME_WAIT sockets currently
have a zero skb->priority, which can cause various problems.

In this patch we :

- add a tw_priority field in struct inet_timewait_sock.

- populate it from sk->sk_priority when a TIME_WAIT is created.

- For IPv4, change ip_send_unicast_reply() and its two
  callers to propagate tw_priority correctly.
  ip_send_unicast_reply() no longer changes sk->sk_priority.

- For IPv6, make sure TIME_WAIT sockets pass their tw_priority
  field to tcp_v6_send_response() and tcp_v6_send_ack().

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e9a5dcee

include/net/inet_timewait_sock.h

+1 −0
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ struct inet_timewait_sock { 
				tw_pad		: 2,	/* 2 bits hole */

				tw_tos		: 8;

	u32			tw_txhash;

	u32			tw_priority;

	struct timer_list	tw_timer;

	struct inet_bind_bucket	*tw_tb;

};

net/ipv4/ip_output.c

+0 −1
Original line number Diff line number Diff line
@@ -1694,7 +1694,6 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, 


	inet_sk(sk)->tos = arg->tos;



	sk->sk_priority = skb->priority;

	sk->sk_protocol = ip_hdr(skb)->protocol;

	sk->sk_bound_dev_if = arg->bound_dev_if;

	sk->sk_sndbuf = sysctl_wmem_default;

net/ipv4/tcp_ipv4.c

+4 −0
Original line number Diff line number Diff line
@@ -771,6 +771,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) 
	if (sk) {

		ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?

				   inet_twsk(sk)->tw_mark : sk->sk_mark;

		ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ?

				   inet_twsk(sk)->tw_priority : sk->sk_priority;

		transmit_time = tcp_transmit_time(sk);

	}

	ip_send_unicast_reply(ctl_sk,
@@ -866,6 +868,8 @@ static void tcp_v4_send_ack(const struct sock *sk, 
	ctl_sk = this_cpu_read(*net->ipv4.tcp_sk);

	ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?

			   inet_twsk(sk)->tw_mark : sk->sk_mark;

	ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ?

			   inet_twsk(sk)->tw_priority : sk->sk_priority;

	transmit_time = tcp_transmit_time(sk);

	ip_send_unicast_reply(ctl_sk,

			      skb, &TCP_SKB_CB(skb)->header.h4.opt,

net/ipv4/tcp_minisocks.c

+1 −0
Original line number Diff line number Diff line
@@ -266,6 +266,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) 


		tw->tw_transparent	= inet->transparent;

		tw->tw_mark		= sk->sk_mark;

		tw->tw_priority		= sk->sk_priority;

		tw->tw_rcv_wscale	= tp->rx_opt.rcv_wscale;

		tcptw->tw_rcv_nxt	= tp->rcv_nxt;

		tcptw->tw_snd_nxt	= tp->snd_nxt;

net/ipv6/tcp_ipv6.c

+4 −2
Original line number Diff line number Diff line
@@ -995,8 +995,10 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) 
				label = ip6_flowlabel(ipv6h);

			priority = sk->sk_priority;

		}

		if (sk->sk_state == TCP_TIME_WAIT)

		if (sk->sk_state == TCP_TIME_WAIT) {

			label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);

			priority = inet_twsk(sk)->tw_priority;

		}

	} else {

		if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)

			label = ip6_flowlabel(ipv6h);
@@ -1029,7 +1031,7 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) 
			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,

			tcp_time_stamp_raw() + tcptw->tw_ts_offset,

			tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),

			tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), 0);

			tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority);



	inet_twsk_put(tw);

}

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