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 3b067704ab38..748cb5b337bd 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 46eb3dc37ec6..eb68a0e34e49 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 ea28fa5f1992..04c7b3ba6b39 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 f1309072c541..1ff79e557f96 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 90b5a37555ab..770f70427f0b 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 1b4ec21497a4..e85ff5930607 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 63b854e74d99..534972e114ac 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;