linux-stable.git/include/net/if_inet6.h, branch linux-3.13.y

ipv6: simplify detection of first operational link-local address on interface

2014-01-18T02:10:01+00:00

In commit 1ec047eb4751e3 ("ipv6: introduce per-interface counter for
dad-completed ipv6 addresses") I build the detection of the first
operational link-local address much to complex. Additionally this code
now has a race condition.

Replace it with a much simpler variant, which just scans the address
list when duplicate address detection completes, to check if this is
the first valid link local address and send RS and MLD reports then.

Fixes: 1ec047eb4751e3 ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses")
Reported-by: Jiri Pirko 
Cc: Flavio Leitner 
Signed-off-by: Hannes Frederic Sowa 
Acked-by: Flavio Leitner 
Acked-by: Jiri Pirko 
Signed-off-by: David S. Miller

ipv6: Remove privacy config option.

2013-10-29T00:07:50+00:00

The code for privacy extentions is very mature, and making it
configurable only gives marginal memory/code savings in exchange
for obfuscation and hard to read code via CPP ifdef'ery.

Signed-off-by: David S. Miller

net: ipv6: mld: fix v1/v2 switchback timeout to rfc3810, 9.12.

2013-09-04T18:53:20+00:00

i) RFC3810, 9.2. Query Interval [QI] says:

   The Query Interval variable denotes the interval between General
   Queries sent by the Querier. Default value: 125 seconds. [...]

ii) RFC3810, 9.3. Query Response Interval [QRI] says:

  The Maximum Response Delay used to calculate the Maximum Response
  Code inserted into the periodic General Queries. Default value:
  10000 (10 seconds) [...] The number of seconds represented by the
  [Query Response Interval] must be less than the [Query Interval].

iii) RFC3810, 9.12. Older Version Querier Present Timeout [OVQPT] says:

  The Older Version Querier Present Timeout is the time-out for
  transitioning a host back to MLDv2 Host Compatibility Mode. When an
  MLDv1 query is received, MLDv2 hosts set their Older Version Querier
  Present Timer to [Older Version Querier Present Timeout].

  This value MUST be ([Robustness Variable] times (the [Query Interval]
  in the last Query received)) plus ([Query Response Interval]).

Hence, on *default* the timeout results in:

  [RV] = 2, [QI] = 125sec, [QRI] = 10sec
  [OVQPT] = [RV] * [QI] + [QRI] = 260sec

Having that said, we currently calculate [OVQPT] (here given as 'switchback'
variable) as ...

  switchback = (idev->mc_qrv + 1) * max_delay

RFC3810, 9.12. says "the [Query Interval] in the last Query received". In
section "9.14. Configuring timers", it is said:

  This section is meant to provide advice to network administrators on
  how to tune these settings to their network. Ambitious router
  implementations might tune these settings dynamically based upon
  changing characteristics of the network. [...]

iv) RFC38010, 9.14.2. Query Interval:

  The overall level of periodic MLD traffic is inversely proportional
  to the Query Interval. A longer Query Interval results in a lower
  overall level of MLD traffic. The value of the Query Interval MUST
  be equal to or greater than the Maximum Response Delay used to
  calculate the Maximum Response Code inserted in General Query
  messages.

I assume that was why switchback is calculated as is (3 * max_delay), although
this setting seems to be meant for routers only to configure their [QI]
interval for non-default intervals. So usage here like this is clearly wrong.

Concluding, the current behaviour in IPv6's multicast code is not conform
to the RFC as switch back is calculated wrongly. That is, it has a too small
value, so MLDv2 hosts switch back again to MLDv2 way too early, i.e. ~30secs
instead of ~260secs on default.

Hence, introduce necessary helper functions and fix this up properly as it
should be.

Introduced in 06da92283 ("[IPV6]: Add MLDv2 support."). Credits to Hannes
Frederic Sowa who also had a hand in this as well. Also thanks to Hangbin Liu
who did initial testing.

Signed-off-by: Daniel Borkmann 
Cc: David Stevens 
Cc: Hannes Frederic Sowa 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

ipv6: resend MLD report if a link-local address completes DAD

2013-06-29T04:19:17+00:00

RFC3590/RFC3810 specifies we should resend MLD reports as soon as a
valid link-local address is available.

We now use the valid_ll_addr_cnt to check if it is necessary to resend
a new report.

Changes since Flavio Leitner's version:
a) adapt for valid_ll_addr_cnt
b) resend first reports directly in the path and just arm the timer for
   mc_qrv-1 resends.

Reported-by: Flavio Leitner 
Cc: Hideaki YOSHIFUJI 
Cc: David Stevens 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: Flavio Leitner 
Signed-off-by: David S. Miller

ipv6: introduce per-interface counter for dad-completed ipv6 addresses

2013-06-29T04:19:17+00:00

To reduce the number of unnecessary router solicitations, MLDv2 and IGMPv3
messages we need to track the number of valid (as in non-optimistic,
no-dad-failed and non-tentative) link-local addresses. Therefore, this
patch implements a valid_ll_addr_cnt in struct inet6_dev.

We now only emit router solicitations if the first link-local address
finishes duplicate address detection.

The changes for MLDv2 and IGMPv3 are in a follow-up patch.

While there, also simplify one if statement(one minor nit I made in one
of my previous patches):

if (!...)
	do();
else
	return;

<>

if (...)
	return;
do();

Cc: Flavio Leitner 
Cc: YOSHIFUJI Hideaki 
Cc: David Stevens 
Suggested-by: David Stevens 
Signed-off-by: Hannes Frederic Sowa 
Acked-by: Flavio Leitner 
Signed-off-by: David S. Miller

ipv6: split duplicate address detection and router solicitation timer

2013-06-25T23:23:03+00:00

This patch splits the timers for duplicate address detection and router
solicitations apart. The router solicitations timer goes into inet6_dev
and the dad timer stays in inet6_ifaddr.

The reason behind this patch is to reduce the number of unneeded router
solicitations send out by the host if additional link-local addresses
are created. Currently we send out RS for every link-local address on
an interface.

If the RS timer fires we pick a source address with ipv6_get_lladdr. This
change could hurt people adding additional link-local addresses and
specifying these addresses in the radvd clients section because we
no longer guarantee that we use every ll address as source address in
router solicitations.

Cc: Flavio Leitner 
Cc: Hideaki YOSHIFUJI 
Cc: David Stevens 
Signed-off-by: Hannes Frederic Sowa 
Reviewed-by: Flavio Leitner 
Signed-off-by: David S. Miller

net: ipv6: remove 'next' member from inet6_dev

2013-05-20T20:49:48+00:00

The next pointer within the inet6_dev structure seems not to be used
anywhere. So just remove it. Tested with allmodconfig on x86_64.

Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

ipv6: add support of peer address

2013-05-19T22:09:26+00:00

This patch adds the support of peer address for IPv6. For example, it is
possible to specify the remote end of a 6inY tunnel.
This was already possible in IPv4:
 ip addr add ip1 peer ip2 dev dev1

The peer address is specified with IFA_ADDRESS and the local address with
IFA_LOCAL (like explained in include/uapi/linux/if_addr.h).
Note that the API is not changed, because before this patch, it was not
possible to specify two different addresses in IFA_LOCAL and IFA_REMOTE.
There is a small change for the dump: if the peer is different from ::,
IFA_ADDRESS will contain the peer address instead of the local address.

Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller

net: ipv6: only invalidate previously tokenized addresses

2013-04-09T17:12:23+00:00

Instead of invalidating all IPv6 addresses with global scope
when one decides to use IPv6 tokens, we should only invalidate
previous tokens and leave the rest intact until they expire
eventually (or are intact forever). For doing this less greedy
approach, we're adding a bool at the end of inet6_ifaddr structure
instead, for two reasons: i) per-inet6_ifaddr flag space is
already used up, making it wider might not be a good idea,
since ii) also we do not necessarily need to export this
information into user space.

Suggested-by: Hannes Frederic Sowa 
Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net: ipv6: add tokenized interface identifier support

2013-04-08T20:55:28+00:00

This patch adds support for IPv6 tokenized IIDs, that allow
for administrators to assign well-known host-part addresses
to nodes whilst still obtaining global network prefix from
Router Advertisements. It is currently in draft status.

  The primary target for such support is server platforms
  where addresses are usually manually configured, rather
  than using DHCPv6 or SLAAC. By using tokenised identifiers,
  hosts can still determine their network prefix by use of
  SLAAC, but more readily be automatically renumbered should
  their network prefix change. [...]

  The disadvantage with static addresses is that they are
  likely to require manual editing should the network prefix
  in use change.  If instead there were a method to only
  manually configure the static identifier part of the IPv6
  address, then the address could be automatically updated
  when a new prefix was introduced, as described in [RFC4192]
  for example.  In such cases a DNS server might be
  configured with such a tokenised interface identifier of
  ::53, and SLAAC would use the token in constructing the
  interface address, using the advertised prefix. [...]

  http://tools.ietf.org/html/draft-chown-6man-tokenised-ipv6-identifiers-02

The implementation is partially based on top of Mark K.
Thompson's proof of concept. However, it uses the Netlink
interface for configuration resp. data retrival, so that
it can be easily extended in future. Successfully tested
by myself.

Cc: Hannes Frederic Sowa 
Cc: YOSHIFUJI Hideaki 
Cc: Thomas Graf 
Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller