[IPV6]: make extended headers to return an error at initialization

This patch factorize the code for the differents init functions for rthdr,
nodata, destopt in a single function exthdrs_init.
This function returns an error so the af_inet6 module can check correctly
the initialization.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index cee06b1..2df34ed 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -308,28 +308,6 @@
 	return -1;
 }
 
-static struct inet6_protocol destopt_protocol = {
-	.handler	=	ipv6_destopt_rcv,
-	.flags		=	INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
-};
-
-void __init ipv6_destopt_init(void)
-{
-	if (inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS) < 0)
-		printk(KERN_ERR "ipv6_destopt_init: Could not register protocol\n");
-}
-
-static struct inet6_protocol nodata_protocol = {
-	.handler	=	dst_discard,
-	.flags		=	INET6_PROTO_NOPOLICY,
-};
-
-void __init ipv6_nodata_init(void)
-{
-	if (inet6_add_protocol(&nodata_protocol, IPPROTO_NONE) < 0)
-		printk(KERN_ERR "ipv6_nodata_init: Could not register protocol\n");
-}
-
 /********************************
   Routing header.
  ********************************/
@@ -527,12 +505,48 @@
 	.flags		=	INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
 };
 
-void __init ipv6_rthdr_init(void)
-{
-	if (inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING) < 0)
-		printk(KERN_ERR "ipv6_rthdr_init: Could not register protocol\n");
+static struct inet6_protocol destopt_protocol = {
+	.handler	=	ipv6_destopt_rcv,
+	.flags		=	INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
 };
 
+static struct inet6_protocol nodata_protocol = {
+	.handler	=	dst_discard,
+	.flags		=	INET6_PROTO_NOPOLICY,
+};
+
+int __init ipv6_exthdrs_init(void)
+{
+	int ret;
+
+	ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
+	if (ret)
+		goto out;
+
+	ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
+	if (ret)
+		goto out_rthdr;
+
+	ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
+	if (ret)
+		goto out_destopt;
+
+out:
+	return ret;
+out_rthdr:
+	inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
+out_destopt:
+	inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
+	goto out;
+};
+
+void ipv6_exthdrs_exit(void)
+{
+	inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
+	inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
+	inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
+}
+
 /**********************************
   Hop-by-hop options.
  **********************************/