Patchwork Do not leave router anycast address for /127 prefixes.

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Submitter YOSHIFUJI Hideaki / 吉藤英明
Date July 24, 2011, 9:44 p.m.
Message ID <1311543874-16901-1-git-send-email-yoshfuji@linux-ipv6.org>
Download mbox | patch
Permalink /patch/106575/
State Accepted
Delegated to: David Miller
Headers show

Comments

YOSHIFUJI Hideaki / 吉藤英明 - July 24, 2011, 9:44 p.m.
From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Original commit 2bda8a0c8af... "Disable router anycast
address for /127 prefixes" says:

|   No need for matching code in addrconf_leave_anycast() as it
|   will silently ignore any attempt to leave an unknown anycast
|   address.

After analysis, because 1) we may add two or more prefixes on the
same interface, or 2)user may have manually joined that anycast,
we may hit chances to have anycast address which as if we had
generated one by /127 prefix and we should not leave from subnet-
router anycast address unconditionally.

CC: Bjørn Mork <bjorn@mork.no>
CC: Brian Haley <brian.haley@hp.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
---
 net/ipv6/addrconf.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
David Miller - July 25, 2011, 11:16 p.m.
From: yoshfuji@linux-ipv6.org
Date: Mon, 25 Jul 2011 06:44:34 +0900

> From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> 
> Original commit 2bda8a0c8af... "Disable router anycast
> address for /127 prefixes" says:
> 
> |   No need for matching code in addrconf_leave_anycast() as it
> |   will silently ignore any attempt to leave an unknown anycast
> |   address.
> 
> After analysis, because 1) we may add two or more prefixes on the
> same interface, or 2)user may have manually joined that anycast,
> we may hit chances to have anycast address which as if we had
> generated one by /127 prefix and we should not leave from subnet-
> router anycast address unconditionally.
> 
> CC: Bjørn Mork <bjorn@mork.no>
> CC: Brian Haley <brian.haley@hp.com>
> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Applied.
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Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a06c53c..a55500c 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1481,6 +1481,8 @@  static void addrconf_join_anycast(struct inet6_ifaddr *ifp)
 static void addrconf_leave_anycast(struct inet6_ifaddr *ifp)
 {
 	struct in6_addr addr;
+	if (ifp->prefix_len == 127) /* RFC 6164 */
+		return;
 	ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
 	if (ipv6_addr_any(&addr))
 		return;