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Diffstat (limited to 'net/ipv4/ip_output.c')
-rw-r--r--net/ipv4/ip_output.c93
1 files changed, 50 insertions, 43 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 451f97c..ba39a52 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -113,19 +113,6 @@ int ip_local_out(struct sk_buff *skb)
}
EXPORT_SYMBOL_GPL(ip_local_out);
-/* dev_loopback_xmit for use with netfilter. */
-static int ip_dev_loopback_xmit(struct sk_buff *newskb)
-{
- skb_reset_mac_header(newskb);
- __skb_pull(newskb, skb_network_offset(newskb));
- newskb->pkt_type = PACKET_LOOPBACK;
- newskb->ip_summed = CHECKSUM_UNNECESSARY;
- WARN_ON(!skb_dst(newskb));
- skb_dst_force(newskb);
- netif_rx_ni(newskb);
- return 0;
-}
-
static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
{
int ttl = inet->uc_ttl;
@@ -183,6 +170,7 @@ static inline int ip_finish_output2(struct sk_buff *skb)
struct net_device *dev = dst->dev;
unsigned int hh_len = LL_RESERVED_SPACE(dev);
struct neighbour *neigh;
+ u32 nexthop;
if (rt->rt_type == RTN_MULTICAST) {
IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len);
@@ -200,19 +188,22 @@ static inline int ip_finish_output2(struct sk_buff *skb)
}
if (skb->sk)
skb_set_owner_w(skb2, skb->sk);
- kfree_skb(skb);
+ consume_skb(skb);
skb = skb2;
}
- rcu_read_lock();
- neigh = dst_get_neighbour_noref(dst);
+ rcu_read_lock_bh();
+ nexthop = rt->rt_gateway ? rt->rt_gateway : ip_hdr(skb)->daddr;
+ neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
+ if (unlikely(!neigh))
+ neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
if (neigh) {
- int res = neigh_output(neigh, skb);
+ int res = dst_neigh_output(dst, neigh, skb);
- rcu_read_unlock();
+ rcu_read_unlock_bh();
return res;
}
- rcu_read_unlock();
+ rcu_read_unlock_bh();
net_dbg_ratelimited("%s: No header cache and no neighbour!\n",
__func__);
@@ -281,7 +272,7 @@ int ip_mc_output(struct sk_buff *skb)
if (newskb)
NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING,
newskb, NULL, newskb->dev,
- ip_dev_loopback_xmit);
+ dev_loopback_xmit);
}
/* Multicasts with ttl 0 must not go beyond the host */
@@ -296,7 +287,7 @@ int ip_mc_output(struct sk_buff *skb)
struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
if (newskb)
NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, newskb,
- NULL, newskb->dev, ip_dev_loopback_xmit);
+ NULL, newskb->dev, dev_loopback_xmit);
}
return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL,
@@ -380,7 +371,7 @@ int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl)
skb_dst_set_noref(skb, &rt->dst);
packet_routed:
- if (inet_opt && inet_opt->opt.is_strictroute && fl4->daddr != rt->rt_gateway)
+ if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_gateway)
goto no_route;
/* OK, we know where to send it, allocate and build IP header. */
@@ -709,7 +700,7 @@ slow_path:
IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES);
}
- kfree_skb(skb);
+ consume_skb(skb);
IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS);
return err;
@@ -1472,19 +1463,34 @@ 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. ICMP should use this function too.
+ * 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_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
- const struct ip_reply_arg *arg, unsigned int len)
+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,
+ .uc_ttl = -1,
+};
+
+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;
@@ -1502,38 +1508,39 @@ void ip_send_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, rt->rt_spec_dst,
+ 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);
}
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