IPv6 and rt6_lookup()

2006-11-02 Thread Nicolas DICHTEL

Hello,

Suppose that a host has autoconfiguration enabled. It will take RA to
autoconfigure an IPv6 address. For example, 
2001:0db8:3008:c1ca:2d0:b7ff:febb:4aee/64.
This host will create a route entry for this onlink prefix (dst: 
2001:0db8:3008:c1ca::/64)

in the MAIN table with the lifetime present in prefix option in RA.
Each time this host will receive a RA, it will update this lifetime. To 
do this,

it will call rt6_lookup() (in addrconf_prefix_rcv()) to find the entry.

Now, suppose that our host joins this anycast group: 
2001:0db8:3008:c1ca::0. A route

entry will be added in the LOCAL table (see addrconf_join_anycast()).
Problem is that, next time our host will receive a RA and will perform a 
rt6_lookup(),
this function will return the local entry (LOCAL table), and not the 
dynamic entry
(MAIN table). Consequence is that the lifetime of the dynamic entry will 
never been updated,

and so will expire, whereas the host will keep the corresponding address.

Maybe, when strict is set to 1 in rt6_lookup(), kernel must not return 
an anycast route.

What about this patch ?


Regards,
Nicolas

[IPv6] Don't return anycast route when strict is enable

Signed-off-by: Nicolas DICHTEL [EMAIL PROTECTED]

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index c953466..51a8c1d 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -248,6 +248,8 @@ static __inline__ struct rt6_info *rt6_d
 			if (dev-ifindex == oif)
 return sprt;
 			if (dev-flags  IFF_LOOPBACK) {
+if (strict  sprt-rt6i_flags  RTF_ANYCAST)
+	continue;
 if (sprt-rt6i_idev == NULL ||
 sprt-rt6i_idev-dev-ifindex != oif) {
 	if (strict  oif)


Re: IPv6 and rt6_lookup()

2006-11-02 Thread Vlad Yasevich
Nicolas DICHTEL wrote:
 Hello,
 
 Suppose that a host has autoconfiguration enabled. It will take RA to
 autoconfigure an IPv6 address. For example,
 2001:0db8:3008:c1ca:2d0:b7ff:febb:4aee/64.
 This host will create a route entry for this onlink prefix (dst:
 2001:0db8:3008:c1ca::/64)
 in the MAIN table with the lifetime present in prefix option in RA.
 Each time this host will receive a RA, it will update this lifetime. To
 do this,
 it will call rt6_lookup() (in addrconf_prefix_rcv()) to find the entry.
 
 Now, suppose that our host joins this anycast group:
 2001:0db8:3008:c1ca::0. A route

Hmm... you are configuring a subnet router anycast address on host and 
the implementation lets you do it?  That's not good.  I don't think
you sould be permitted to configure a subnet router anycast address
on a host that autoconfigures it's interface.

-vlad

 entry will be added in the LOCAL table (see addrconf_join_anycast()).
 Problem is that, next time our host will receive a RA and will perform a
 rt6_lookup(),
 this function will return the local entry (LOCAL table), and not the
 dynamic entry
 (MAIN table). Consequence is that the lifetime of the dynamic entry will
 never been updated,
 and so will expire, whereas the host will keep the corresponding address.
 
 Maybe, when strict is set to 1 in rt6_lookup(), kernel must not return
 an anycast route.
 What about this patch ?
 
 
 Regards,
 Nicolas
 
 [IPv6] Don't return anycast route when strict is enable
 
 Signed-off-by: Nicolas DICHTEL [EMAIL PROTECTED]
 
 
 
 
 diff --git a/net/ipv6/route.c b/net/ipv6/route.c
 index c953466..51a8c1d 100644
 --- a/net/ipv6/route.c
 +++ b/net/ipv6/route.c
 @@ -248,6 +248,8 @@ static __inline__ struct rt6_info *rt6_d
   if (dev-ifindex == oif)
   return sprt;
   if (dev-flags  IFF_LOOPBACK) {
 + if (strict  sprt-rt6i_flags  RTF_ANYCAST)
 + continue;
   if (sprt-rt6i_idev == NULL ||
   sprt-rt6i_idev-dev-ifindex != oif) {
   if (strict  oif)

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Re: IPv6 and rt6_lookup()

2006-11-02 Thread Nicolas DICHTEL

Le 02.11.2006 18:02, Vlad Yasevich a écrit :

Nicolas DICHTEL wrote:

Hello,

Suppose that a host has autoconfiguration enabled. It will take RA to
autoconfigure an IPv6 address. For example,
2001:0db8:3008:c1ca:2d0:b7ff:febb:4aee/64.
This host will create a route entry for this onlink prefix (dst:
2001:0db8:3008:c1ca::/64)
in the MAIN table with the lifetime present in prefix option in RA.
Each time this host will receive a RA, it will update this lifetime. To
do this,
it will call rt6_lookup() (in addrconf_prefix_rcv()) to find the entry.

Now, suppose that our host joins this anycast group:
2001:0db8:3008:c1ca::0. A route


Hmm... you are configuring a subnet router anycast address on host and 
the implementation lets you do it?  That's not good.  I don't think

you sould be permitted to configure a subnet router anycast address
on a host that autoconfigures it's interface.
The current implementation allow this and I don't know if we must 
prohibit this.
For example, in case of NEMO (RFC3963), router may autoconfigured its 
address.


Nicolas
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