[NETNS][IPV6] ip6_fib - add net to gc timer parameter

The fib tables are now relative to the network namespace. When the
garbage collector timer expires, we must have a network namespace
parameter in order to retrieve the tables. For now this is the
init_net, but we should be able to have a timer per namespace and use
the timer callback parameter to pass the network namespace from the
expired timer.

The timer callback, fib6_run_gc, is actually used to be called
synchronously by some functions and asynchronously when the timer
expires.

When the timer expires, the delay specified for fib6_run_gc parameter
is always zero. So, I changed fib6_run_gc to not be a timer callback
but a function called by the timer callback and I added a timer
callback where its work is just to retrieve from the data arg of the
timer the network namespace and call fib6_run_gc with zero expiring
time and the network namespace parameters. That makes the code cleaner
for the fib6_run_gc callers.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2e6da2a..fd44721 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -40,6 +40,7 @@
 #include <linux/if_arp.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/nsproxy.h>
 #include <net/net_namespace.h>
 #include <net/snmp.h>
 #include <net/ipv6.h>
@@ -995,7 +996,7 @@
 		goto out;
 
 	expire++;
-	fib6_run_gc(expire);
+	fib6_run_gc(expire, &init_net);
 	last_gc = now;
 	if (atomic_read(&ip6_dst_ops.entries) < ip6_dst_ops.gc_thresh)
 		expire = init_net.ipv6.sysctl.ip6_rt_gc_timeout>>1;
@@ -2413,10 +2414,11 @@
 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write, struct file * filp,
 			      void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-	int delay = init_net.ipv6.sysctl.flush_delay;
+	struct net *net = current->nsproxy->net_ns;
+	int delay = net->ipv6.sysctl.flush_delay;
 	if (write) {
 		proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
-		fib6_run_gc(delay <= 0 ? ~0UL : (unsigned long)delay);
+		fib6_run_gc(delay <= 0 ? ~0UL : (unsigned long)delay, net);
 		return 0;
 	} else
 		return -EINVAL;