aboutsummaryrefslogtreecommitdiffstats
path: root/net/ipv4/tcp_ipv4.c
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2015-01-29 21:35:05 -0800
committerDavid S. Miller <davem@davemloft.net>2015-02-01 23:06:19 -0800
commitbdbbb8527b6f6a358dbcb70dac247034d665b8e4 (patch)
treed3c764600d9d7a18956943fcb5c0de8f2e0a6c43 /net/ipv4/tcp_ipv4.c
parentnet: sched: fix panic in rate estimators (diff)
downloadlinux-dev-bdbbb8527b6f6a358dbcb70dac247034d665b8e4.tar.xz
linux-dev-bdbbb8527b6f6a358dbcb70dac247034d665b8e4.zip
ipv4: tcp: get rid of ugly unicast_sock
In commit be9f4a44e7d41 ("ipv4: tcp: remove per net tcp_sock") I tried to address contention on a socket lock, but the solution I chose was horrible : commit 3a7c384ffd57e ("ipv4: tcp: unicast_sock should not land outside of TCP stack") addressed a selinux regression. commit 0980e56e506b ("ipv4: tcp: set unicast_sock uc_ttl to -1") took care of another regression. commit b5ec8eeac46 ("ipv4: fix ip_send_skb()") fixed another regression. commit 811230cd85 ("tcp: ipv4: initialize unicast_sock sk_pacing_rate") was another shot in the dark. Really, just use a proper socket per cpu, and remove the skb_orphan() call, to re-enable flow control. This solves a serious problem with FQ packet scheduler when used in hostile environments, as we do not want to allocate a flow structure for every RST packet sent in response to a spoofed packet. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c37
1 files changed, 32 insertions, 5 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index a3f72d7fc06c..d22f54482bab 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -683,7 +683,8 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
arg.bound_dev_if = sk->sk_bound_dev_if;
arg.tos = ip_hdr(skb)->tos;
- ip_send_unicast_reply(net, skb, &TCP_SKB_CB(skb)->header.h4.opt,
+ ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
+ skb, &TCP_SKB_CB(skb)->header.h4.opt,
ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
&arg, arg.iov[0].iov_len);
@@ -767,7 +768,8 @@ static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
if (oif)
arg.bound_dev_if = oif;
arg.tos = tos;
- ip_send_unicast_reply(net, skb, &TCP_SKB_CB(skb)->header.h4.opt,
+ ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
+ skb, &TCP_SKB_CB(skb)->header.h4.opt,
ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
&arg, arg.iov[0].iov_len);
@@ -2428,14 +2430,39 @@ struct proto tcp_prot = {
};
EXPORT_SYMBOL(tcp_prot);
+static void __net_exit tcp_sk_exit(struct net *net)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.tcp_sk, cpu));
+ free_percpu(net->ipv4.tcp_sk);
+}
+
static int __net_init tcp_sk_init(struct net *net)
{
+ int res, cpu;
+
+ net->ipv4.tcp_sk = alloc_percpu(struct sock *);
+ if (!net->ipv4.tcp_sk)
+ return -ENOMEM;
+
+ for_each_possible_cpu(cpu) {
+ struct sock *sk;
+
+ res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW,
+ IPPROTO_TCP, net);
+ if (res)
+ goto fail;
+ *per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk;
+ }
net->ipv4.sysctl_tcp_ecn = 2;
return 0;
-}
-static void __net_exit tcp_sk_exit(struct net *net)
-{
+fail:
+ tcp_sk_exit(net);
+
+ return res;
}
static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)