ipv4: Don't pre-seed hoplimit metric.

Always go through a new ip4_dst_hoplimit() helper, just like ipv6.

This allowed several simplifications:

1) The interim dst_metric_hoplimit() can go as it's no longer
   userd.

2) The sysctl_ip_default_ttl entry no longer needs to use
   ipv4_doint_and_flush, since the sysctl is not cached in
   routing cache metrics any longer.

3) ipv4_doint_and_flush no longer needs to be exported and
   therefore can be marked static.

When ipv4_doint_and_flush_strategy was removed some time ago,
the external declaration in ip.h was mistakenly left around
so kill that off too.

We have to move the sysctl_ip_default_ttl declaration into
ipv4's route cache definition header net/route.h, because
currently net/ip.h (where the declaration lives now) has
a back dependency on net/route.h

Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 9 insertions, 10 deletions

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 3b06770..748cb5b 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1430,9 +1430,9 @@ static int devinet_sysctl_forward(ctl_table *ctl, int write,
 	return ret;
 }
 
-int ipv4_doint_and_flush(ctl_table *ctl, int write,
-			 void __user *buffer,
-			 size_t *lenp, loff_t *ppos)
+static int ipv4_doint_and_flush(ctl_table *ctl, int write,
+				void __user *buffer,
+				size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 46eb3dc..eb68a0e 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -890,7 +890,7 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
 			iph->ttl = ((struct ipv6hdr *)old_iph)->hop_limit;
 #endif
 		else
-			iph->ttl = dst_metric_hoplimit(&rt->dst);
+			iph->ttl = ip4_dst_hoplimit(&rt->dst);
 	}
 
 	((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index ea28fa5..04c7b3b 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -82,6 +82,7 @@
 #include <linux/tcp.h>
 
 int sysctl_ip_default_ttl __read_mostly = IPDEFTTL;
+EXPORT_SYMBOL(sysctl_ip_default_ttl);
 
 /* Generate a checksum for an outgoing IP datagram. */
 __inline__ void ip_send_check(struct iphdr *iph)
@@ -130,7 +131,7 @@ static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
 	int ttl = inet->uc_ttl;
 
 	if (ttl < 0)
-		ttl = dst_metric_hoplimit(dst);
+		ttl = ip4_dst_hoplimit(dst);
 	return ttl;
 }
 
diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c
index f130907..1ff79e5 100644
--- a/net/ipv4/netfilter/ipt_REJECT.c
+++ b/net/ipv4/netfilter/ipt_REJECT.c
@@ -116,7 +116,7 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 	if (ip_route_me_harder(nskb, addr_type))
 		goto free_nskb;
 
-	niph->ttl	= dst_metric_hoplimit(skb_dst(nskb));
+	niph->ttl	= ip4_dst_hoplimit(skb_dst(nskb));
 
 	/* "Never happens" */
 	if (nskb->len > dst_mtu(skb_dst(nskb)))
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 90b5a37..770f704 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1821,8 +1821,6 @@ static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
 	} else
 		dst_metric_set(dst, RTAX_MTU, dst->dev->mtu);
 
-	if (dst_metric_raw(dst, RTAX_HOPLIMIT) == 0)
-		dst_metric_set(dst, RTAX_HOPLIMIT, sysctl_ip_default_ttl);
 	if (dst_mtu(dst) > IP_MAX_MTU)
 		dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
 	if (dst_metric(dst, RTAX_ADVMSS) == 0)
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 1b4ec21..e85ff59 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -155,7 +155,7 @@ static struct ctl_table ipv4_table[] = {
 		.data		= &sysctl_ip_default_ttl,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= ipv4_doint_and_flush,
+		.proc_handler	= proc_dointvec,
 		.extra2		= &init_net,
 	},
 	{
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index 63b854e..534972e 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -56,7 +56,7 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 		0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
 	ip_select_ident(top_iph, dst->child, NULL);
 
-	top_iph->ttl = dst_metric_hoplimit(dst->child);
+	top_iph->ttl = ip4_dst_hoplimit(dst->child);
 
 	top_iph->saddr = x->props.saddr.a4;
 	top_iph->daddr = x->id.daddr.a4;