[IPV6]: Make ip6_route_init to return an error code.

The route initialization function does not return any value to notify
if the initialization is successful or not. This patch checks all
calls made for the initilization in order to return a value for the
caller.

Unfortunately, proc_net_fops_create will return a NULL pointer if
CONFIG_PROC_FS is off, so we can not check the return code without an
ifdef CONFIG_PROC_FS block in the ip6_route_init function.
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip6_route.h

@@ -50,7 +50,7 @@ extern void			ip6_route_input(struct sk_buff *skb);
 extern struct dst_entry *	ip6_route_output(struct sock *sk,
 						 struct flowi *fl);
 
-extern void			ip6_route_init(void);
+extern int			ip6_route_init(void);
 extern void			ip6_route_cleanup(void);
 
 extern int			ipv6_route_ioctl(unsigned int cmd, void __user *arg);

net/ipv6/route.c

@@ -2468,26 +2468,70 @@ ctl_table ipv6_route_table[] = {
 
 #endif
 
-void __init ip6_route_init(void)
+int __init ip6_route_init(void)
 {
+	int ret;
+
 	ip6_dst_ops.kmem_cachep =
 		kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
 				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
 	ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops.kmem_cachep;
 
-	fib6_init();
-	proc_net_fops_create(&init_net, "ipv6_route", 0, &ipv6_route_proc_fops);
-	proc_net_fops_create(&init_net, "rt6_stats", S_IRUGO, &rt6_stats_seq_fops);
+	ret = fib6_init();
+	if (ret)
+		goto out_kmem_cache;
+
+#ifdef CONFIG_PROC_FS
+	ret = -ENOMEM;
+	if (!proc_net_fops_create(&init_net, "ipv6_route",
+				  0, &ipv6_route_proc_fops))
+		goto out_fib6_init;
+
+	if (!proc_net_fops_create(&init_net, "rt6_stats",
+				  S_IRUGO, &rt6_stats_seq_fops))
+		goto out_proc_ipv6_route;
+#endif
+
 #ifdef CONFIG_XFRM
-	xfrm6_init();
+	ret = xfrm6_init();
+	if (ret)
+		goto out_proc_rt6_stats;
 #endif
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
-	fib6_rules_init();
+	ret = fib6_rules_init();
+	if (ret)
+		goto xfrm6_init;
 #endif
+	ret = -ENOBUFS;
+	if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL) ||
+	    __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL) ||
+	    __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL))
+		goto fib6_rules_init;
+
+	ret = 0;
+out:
+	return ret;
 
-	__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL);
-	__rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL);
-	__rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL);
+fib6_rules_init:
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+	fib6_rules_cleanup();
+xfrm6_init:
+#endif
+#ifdef CONFIG_XFRM
+	xfrm6_fini();
+out_proc_rt6_stats:
+#endif
+#ifdef CONFIG_PROC_FS
+	proc_net_remove(&init_net, "rt6_stats");
+out_proc_ipv6_route:
+	proc_net_remove(&init_net, "ipv6_route");
+out_fib6_init:
+#endif
+	rt6_ifdown(NULL);
+	fib6_gc_cleanup();
+out_kmem_cache:
+	kmem_cache_destroy(ip6_dst_ops.kmem_cachep);
+	goto out;
 }
 
 void ip6_route_cleanup(void)
@@ -2495,10 +2539,8 @@ void ip6_route_cleanup(void)
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 	fib6_rules_cleanup();
 #endif
-#ifdef CONFIG_PROC_FS
 	proc_net_remove(&init_net, "ipv6_route");
 	proc_net_remove(&init_net, "rt6_stats");
-#endif
 #ifdef CONFIG_XFRM
 	xfrm6_fini();
 #endif