[NETNS][ICMP]: Use per-net sysctls in ipv4/icmp.c.

This mostly re-uses the net, used in icmp netnsization patches from Denis.

After this ICMP sysctls are completely virtualized.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/icmp.c

@@ -270,7 +270,8 @@ int xrlim_allow(struct dst_entry *dst, int timeout)
 	return rc;
 }
 
-static inline int icmpv4_xrlim_allow(struct rtable *rt, int type, int code)
+static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
+		int type, int code)
 {
 	struct dst_entry *dst = &rt->u.dst;
 	int rc = 1;
@@ -287,8 +288,8 @@ static inline int icmpv4_xrlim_allow(struct rtable *rt, int type, int code)
 		goto out;
 
 	/* Limit if icmp type is enabled in ratemask. */
-	if ((1 << type) & init_net.ipv4.sysctl_icmp_ratemask)
-		rc = xrlim_allow(dst, init_net.ipv4.sysctl_icmp_ratelimit);
+	if ((1 << type) & net->ipv4.sysctl_icmp_ratemask)
+		rc = xrlim_allow(dst, net->ipv4.sysctl_icmp_ratelimit);
 out:
 	return rc;
 }
@@ -390,7 +391,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 		if (ip_route_output_key(net, &rt, &fl))
 			goto out_unlock;
 	}
-	if (icmpv4_xrlim_allow(rt, icmp_param->data.icmph.type,
+	if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type,
 			       icmp_param->data.icmph.code))
 		icmp_push_reply(icmp_param, &ipc, rt);
 	ip_rt_put(rt);
@@ -501,7 +502,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 		struct net_device *dev = NULL;
 
 		if (rt->fl.iif &&
-			init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
+			net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
 			dev = dev_get_by_index(net, rt->fl.iif);
 
 		if (dev) {
@@ -617,7 +618,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 	}
 
 route_done:
-	if (!icmpv4_xrlim_allow(rt, type, code))
+	if (!icmpv4_xrlim_allow(net, rt, type, code))
 		goto ende;
 
 	/* RFC says return as much as we can without exceeding 576 bytes. */
@@ -723,7 +724,7 @@ static void icmp_unreach(struct sk_buff *skb)
 	 *	get the other vendor to fix their kit.
 	 */
 
-	if (!init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses &&
+	if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses &&
 	    inet_addr_type(net, iph->daddr) == RTN_BROADCAST) {
 		if (net_ratelimit())
 			printk(KERN_WARNING "%u.%u.%u.%u sent an invalid ICMP "
@@ -818,7 +819,10 @@ out_err:
 
 static void icmp_echo(struct sk_buff *skb)
 {
-	if (!init_net.ipv4.sysctl_icmp_echo_ignore_all) {
+	struct net *net;
+
+	net = skb->dst->dev->nd_net;
+	if (!net->ipv4.sysctl_icmp_echo_ignore_all) {
 		struct icmp_bxm icmp_param;
 
 		icmp_param.data.icmph	   = *icmp_hdr(skb);
@@ -1021,6 +1025,9 @@ int icmp_rcv(struct sk_buff *skb)
 	 */
 
 	if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
+		struct net *net;
+
+		net = rt->u.dst.dev->nd_net;
 		/*
 		 *	RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be
 		 *	  silently ignored (we let user decide with a sysctl).
@@ -1029,7 +1036,7 @@ int icmp_rcv(struct sk_buff *skb)
 		 */
 		if ((icmph->type == ICMP_ECHO ||
 		     icmph->type == ICMP_TIMESTAMP) &&
-		    init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts) {
+		    net->ipv4.sysctl_icmp_echo_ignore_broadcasts) {
 			goto error;
 		}
 		if (icmph->type != ICMP_ECHO &&