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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index aef38c140014600dbf88b1d664bad1b0adf63668..dfd919b3119e8efcbc436a67e3e6fbd02091db10 100644 (file)
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -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;
 };

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index a77c3a4c24de40ff6bf3fa9da9a018457139e2b5..28fca408812c5576fc4ea957c1c4dec97ec8faf3 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -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;

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index fd394ad179a008085b4e87215290f243ea1993b6..2ee45e3755e92e60b5e1810e2f68205221b8308d 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -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,

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 8bcaf2586b6892b52fc3b25545017ec21afb0bde..bb140a5db8c066e57f1018fd47bccd4628def642 100644 (file)
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -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;

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 5f557bf27da2ba6bcc74034a53a3f76a99fdf9f4..e3d9f4559c99f252eba448845cce434bc53f3fd8 100644 (file)
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -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);
 }