diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/ip_output.c | 50 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 8 |
2 files changed, 35 insertions, 23 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index cc52679..c528f84 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1463,20 +1463,33 @@ 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 TCP resets so far. + * Used to send some TCP resets/acks so far. * - * Should run single threaded per socket because it uses the sock - * structure to pass arguments. + * Use a fake percpu inet socket to avoid false sharing and contention. */ -void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr, +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), + }, + .pmtudisc = IP_PMTUDISC_WANT, +}; + +void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, __be32 saddr, const struct ip_reply_arg *arg, unsigned int len) { - struct inet_sock *inet = inet_sk(sk); struct ip_options_data replyopts; struct ipcm_cookie ipc; struct flowi4 fl4; struct rtable *rt = skb_rtable(skb); + struct sk_buff *nskb; + struct sock *sk; + struct inet_sock *inet; if (ip_options_echo(&replyopts.opt.opt, skb)) return; @@ -1494,38 +1507,39 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr, flowi4_init_output(&fl4, arg->bound_dev_if, 0, RT_TOS(arg->tos), - RT_SCOPE_UNIVERSE, sk->sk_protocol, + RT_SCOPE_UNIVERSE, ip_hdr(skb)->protocol, ip_reply_arg_flowi_flags(arg), daddr, saddr, tcp_hdr(skb)->source, tcp_hdr(skb)->dest); security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); - rt = ip_route_output_key(sock_net(sk), &fl4); + rt = ip_route_output_key(net, &fl4); if (IS_ERR(rt)) return; - /* And let IP do all the hard work. + inet = &get_cpu_var(unicast_sock); - This chunk is not reenterable, hence spinlock. - Note that it uses the fact, that this function is called - with locally disabled BH and that sk cannot be already spinlocked. - */ - bh_lock_sock(sk); 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; ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, len, 0, &ipc, &rt, MSG_DONTWAIT); - if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { + nskb = skb_peek(&sk->sk_write_queue); + if (nskb) { if (arg->csumoffset >= 0) - *((__sum16 *)skb_transport_header(skb) + - arg->csumoffset) = csum_fold(csum_add(skb->csum, + *((__sum16 *)skb_transport_header(nskb) + + arg->csumoffset) = csum_fold(csum_add(nskb->csum, arg->csum)); - skb->ip_summed = CHECKSUM_NONE; + nskb->ip_summed = CHECKSUM_NONE; + skb_set_queue_mapping(nskb, skb_get_queue_mapping(skb)); ip_push_pending_frames(sk, &fl4); } - bh_unlock_sock(sk); + put_cpu_var(unicast_sock); ip_rt_put(rt); } diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index d9caf5c..d7d2fa5 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -688,7 +688,7 @@ static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) net = dev_net(skb_dst(skb)->dev); arg.tos = ip_hdr(skb)->tos; - ip_send_unicast_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr, + ip_send_unicast_reply(net, skb, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len); TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); @@ -771,7 +771,7 @@ 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->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr, + ip_send_unicast_reply(net, skb, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len); TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); @@ -2624,13 +2624,11 @@ EXPORT_SYMBOL(tcp_prot); static int __net_init tcp_sk_init(struct net *net) { - return inet_ctl_sock_create(&net->ipv4.tcp_sock, - PF_INET, SOCK_RAW, IPPROTO_TCP, net); + return 0; } static void __net_exit tcp_sk_exit(struct net *net) { - inet_ctl_sock_destroy(net->ipv4.tcp_sock); } static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) |