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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/ip_output.c
parent0d32ef8cef9aa8f375e128f78b77caceaa7e8da0 (diff)
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/ip_output.c')
-rw-r--r--net/ipv4/ip_output.c30
1 files changed, 3 insertions, 27 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 38a20a9cca1a..c373c0708d97 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1506,24 +1506,8 @@ static int ip_reply_glue_bits(void *dptr, char *to, int offset,
/*
* Generic function to send a packet as reply to another packet.
* Used to send some TCP resets/acks so far.
- *
- * Use a fake percpu inet socket to avoid false sharing and contention.
*/
-static DEFINE_PER_CPU(struct inet_sock, unicast_sock) = {
- .sk = {
- .__sk_common = {
- .skc_refcnt = ATOMIC_INIT(1),
- },
- .sk_wmem_alloc = ATOMIC_INIT(1),
- .sk_allocation = GFP_ATOMIC,
- .sk_flags = (1UL << SOCK_USE_WRITE_QUEUE),
- .sk_pacing_rate = ~0U,
- },
- .pmtudisc = IP_PMTUDISC_WANT,
- .uc_ttl = -1,
-};
-
-void ip_send_unicast_reply(struct net *net, struct sk_buff *skb,
+void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
const struct ip_options *sopt,
__be32 daddr, __be32 saddr,
const struct ip_reply_arg *arg,
@@ -1533,9 +1517,8 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb,
struct ipcm_cookie ipc;
struct flowi4 fl4;
struct rtable *rt = skb_rtable(skb);
+ struct net *net = sock_net(sk);
struct sk_buff *nskb;
- struct sock *sk;
- struct inet_sock *inet;
int err;
if (__ip_options_echo(&replyopts.opt.opt, skb, sopt))
@@ -1566,15 +1549,11 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb,
if (IS_ERR(rt))
return;
- inet = &get_cpu_var(unicast_sock);
+ inet_sk(sk)->tos = arg->tos;
- inet->tos = arg->tos;
- sk = &inet->sk;
sk->sk_priority = skb->priority;
sk->sk_protocol = ip_hdr(skb)->protocol;
sk->sk_bound_dev_if = arg->bound_dev_if;
- sock_net_set(sk, net);
- __skb_queue_head_init(&sk->sk_write_queue);
sk->sk_sndbuf = sysctl_wmem_default;
err = ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base,
len, 0, &ipc, &rt, MSG_DONTWAIT);
@@ -1590,13 +1569,10 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb,
arg->csumoffset) = csum_fold(csum_add(nskb->csum,
arg->csum));
nskb->ip_summed = CHECKSUM_NONE;
- skb_orphan(nskb);
skb_set_queue_mapping(nskb, skb_get_queue_mapping(skb));
ip_push_pending_frames(sk, &fl4);
}
out:
- put_cpu_var(unicast_sock);
-
ip_rt_put(rt);
}