[IPV6]: ADDRCONF: Use our standard algorithm for randomized ifid.

RFC 3041 describes an algorithm to generate random interface
identifier.  In RFC 3041bis, it is allowed to use different
algorithm than one described in RFC 3041.

So, let's use our standard pseudo random algorithm to simplify
our implementation.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 441eeac..c92f3d6 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -78,8 +78,6 @@
 
 #ifdef CONFIG_IPV6_PRIVACY
 #include <linux/random.h>
-#include <linux/crypto.h>
-#include <linux/scatterlist.h>
 #endif
 
 #include <asm/uaccess.h>
@@ -110,8 +108,6 @@
 static void ipv6_regen_rndid(unsigned long data);
 
 static int desync_factor = MAX_DESYNC_FACTOR * HZ;
-static struct crypto_tfm *md5_tfm;
-static DEFINE_SPINLOCK(md5_tfm_lock);
 #endif
 
 static int ipv6_count_addresses(struct inet6_dev *idev);
@@ -371,8 +367,6 @@
 		in6_dev_hold(ndev);
 
 #ifdef CONFIG_IPV6_PRIVACY
-		get_random_bytes(ndev->rndid, sizeof(ndev->rndid));
-		get_random_bytes(ndev->entropy, sizeof(ndev->entropy));
 		init_timer(&ndev->regen_timer);
 		ndev->regen_timer.function = ipv6_regen_rndid;
 		ndev->regen_timer.data = (unsigned long) ndev;
@@ -1376,34 +1370,9 @@
 /* (re)generation of randomized interface identifier (RFC 3041 3.2, 3.5) */
 static int __ipv6_regen_rndid(struct inet6_dev *idev)
 {
-	struct net_device *dev;
-	struct scatterlist sg[2];
-
-	sg_set_buf(&sg[0], idev->entropy, 8);
-	sg_set_buf(&sg[1], idev->work_eui64, 8);
-
-	dev = idev->dev;
-
-	if (ipv6_generate_eui64(idev->work_eui64, dev)) {
-		printk(KERN_INFO
-			"__ipv6_regen_rndid(idev=%p): cannot get EUI64 identifier; use random bytes.\n",
-			idev);
-		get_random_bytes(idev->work_eui64, sizeof(idev->work_eui64));
-	}
 regen:
-	spin_lock(&md5_tfm_lock);
-	if (unlikely(md5_tfm == NULL)) {
-		spin_unlock(&md5_tfm_lock);
-		return -1;
-	}
-	crypto_digest_init(md5_tfm);
-	crypto_digest_update(md5_tfm, sg, 2);
-	crypto_digest_final(md5_tfm, idev->work_digest);
-	spin_unlock(&md5_tfm_lock);
-
-	memcpy(idev->rndid, &idev->work_digest[0], 8);
+	get_random_bytes(idev->rndid, sizeof(idev->rndid));
 	idev->rndid[0] &= ~0x02;
-	memcpy(idev->entropy, &idev->work_digest[8], 8);
 
 	/*
 	 * <draft-ietf-ipngwg-temp-addresses-v2-00.txt>:
@@ -3759,13 +3728,6 @@
 
 	register_netdevice_notifier(&ipv6_dev_notf);
 
-#ifdef CONFIG_IPV6_PRIVACY
-	md5_tfm = crypto_alloc_tfm("md5", 0);
-	if (unlikely(md5_tfm == NULL))
-		printk(KERN_WARNING
-			"failed to load transform for md5\n");
-#endif
-
 	addrconf_verify(0);
 	rtnetlink_links[PF_INET6] = inet6_rtnetlink_table;
 #ifdef CONFIG_SYSCTL
@@ -3828,11 +3790,6 @@
 
 	rtnl_unlock();
 
-#ifdef CONFIG_IPV6_PRIVACY
-	crypto_free_tfm(md5_tfm);
-	md5_tfm = NULL;
-#endif
-
 #ifdef CONFIG_PROC_FS
 	proc_net_remove("if_inet6");
 #endif