[PATCHES] CTDB: improved IPv6 support
Stefan (metze) Metzmacher
metze at samba.org
Fri Dec 5 07:05:48 MST 2014
Am 05.12.2014 um 15:02 schrieb Amitay Isaacs:
> On Sat, Dec 6, 2014 at 12:42 AM, Stefan (metze) Metzmacher <metze at samba.org>
> wrote:
>
>> Am 05.12.2014 um 14:39 schrieb Amitay Isaacs:
>>> Hi Martin,
>>>
>>> On Thu, Dec 4, 2014 at 11:27 PM, Martin Schwenke <martin at meltin.net>
>> wrote:
>>>
>>>> On Thu, 4 Dec 2014 17:42:51 +1100, Martin Schwenke <martin at meltin.net>
>>>> wrote:
>>>>
>>>>> The attached patch series fixes most problems with IPv6 in CTDB.
>>>>>
>>>>> The most notable things are:
>>>>>
>>>>> * For machine-readable output from the "ctdb" CLI tool, effectively
>>>>> replace "ctdb -Y ..." with "ctdb -X ..." which uses '|' as the field
>>>>> delimiter. For those that don't want '|', they can use
>>>>> "ctdb -x<char> ...".
>>>>>
>>>>> "ctdb -Y ..." is still supported but all documentation and scripts
>>>>> now use "ctdb -X".
>>>>>
>>>>> Mathieu, you're CC:ed because this includes a minor change to the
>>>>> nagios script, which I think is correct but it isn't yet tested. :-)
>>>>>
>>>>> * When the CTDB daemon loads the nodes file it stores a string
>>>>> representation of each node's IP address. This representation is now
>>>>> first converted to canonical form so that IPv6 addresses will
>>>>> compare more reliably.
>>>>>
>>>>> * Some functionality has moved from the daemon to the 10.interfaces
>>>>> eventscript and it now works with IPv6 addresses.
>>>>>
>>>>> For the past couple of years the release IP code in the daemon has
>>>>> depended on being able to determine which interface an IP address is
>>>>> on, rather than trusting vnn->interface. This was done to more
>>>>> reliably be able to remove rogue IP addresses (present due to
>>>>> either race conditions or addresses that have been moved by hand).
>>>>> This is not as easy for IPv6 addresses since the SIOCGIFCONF ioctl
>>>>> does not support IPv6.
>>>>>
>>>>> Therefore, this code has been removed and vnn->interface is now
>>>>> passed to the "releaseip" event, even when it is NULL (in which case
>>>>> "__none__" is passed). In all cases the eventscript now uses some
>> "ip
>>>>> addr show to ..." magic to determine the actual interface and netmask
>>>>> for an IP address being released. If either of these differ from
>>>>> what was passed then a warning is logged, and the actual interface
>>>>> and netmask are used to delete the IP address.
>>>>>
>>>>> I don't think we lost any functionality. The main part of this is in
>>>>> these patches:
>>>>>
>>>>> 32c2eab ctdb-scripts: Make 10.interface IPv6-safe
>>>>> 837f36a ctdb-daemon: Trust vnn->interface for an IP when releasing
>> it
>>>>>
>>>>> * Gratuitous ARP equivalent for IPv6 has been changed to use neighbor
>>>>> advertisements. This seems to work reliably.
>>>>>
>>>>> * Due to duplicate address detection in IPv6, the IP address addition
>>>>> code will try to wait until IPv6 addresses are no longer
>>>>> "tentative". If this times out or "dadfail" occurs then the IP
>>>>> address is removed and the operation fails. Note that this could
>>>>> cause an outage (all nodes unhealthy, one at a time) if a rogue node
>>>>> refuses to release IPs or if CTDB just dies. It isn't possible to
>>>>> easily work around this, so it is a design limitation and may need to
>>>>> be looked at again in the future.
>>>>>
>>>>> This has been tested on a virtual cluster with IPv6 addresses only, on
>>>>> both public and private networks.
>>>>>
>>>>> Please review and push if OK.
>>>>>
>>>>> These patches are in my ctdb-ipv6 branch:
>>>>>
>>>>>
>>>>
>> http://git.samba.org/?p=martins/samba.git;a=shortlog;h=refs/heads/ctdb-ipv6
>>>>>
>>>>> Still to do:
>>>>>
>>>>> * Update policy routing to work with IPv6. There's some code in there
>>>>> that only works for IPv4.
>>>>>
>>>>> * Other features like LVS.
>>>>
>>>> Darn. This looks like it was big enough to be moderated, so...
>>>>
>>>> These patches:
>>>>
>>>> b615d09f ctdb-tools: Produce machine readable output with new function
>>>> printm()
>>>> fdf0461 ctdb-tools: Add -x option to specify delimiter for machine
>>>> readable output
>>>> 42498ee ctdb-tools: Add -X option for machine parsable output with
>>>> separator '|'
>>>> 8485235 ctdb-scripts: Update eventscripts to use ctdb -X instead of
>> ctdb -Y
>>>> 435c200 ctdb-tools: Update onnode and ctdb-diagnostics to use ctdb -X
>>>> 8f1ebc5 ctdb-tests: Update integration tests to use ctdb -X
>>>> 443aa32 ctdb-tool: Fix "ctdb -Y ifaces" output to have trailing
>> delimiters
>>>> c2e39e4 ctdb-doc: Update examples to use ctdb -X
>>>> 1ea9d2e ctdb-utils: Update Nagios code to use ctdb -X
>>>> c6a448c ctdb-scripts: Add IPv6 addresses support in ip_maskbits_iface()
>>>> 9e6d323 ctdb-scripts: New functions ip6tables() and iptables_wrapper()
>>>> 32c2eab ctdb-scripts: Make 10.interface IPv6-safe
>>>> 837f36a ctdb-daemon: Trust vnn->interface for an IP when releasing it
>>>> b7debd7 ctdb-eventscripts: Specify broadcast optionally to ip addr add
>>>> 38a5617 ctdb-scripts: Wait until IPv6 addresses are not "tentative"
>>>> 7944a40 ctdb-daemon: Fix IP address comparisons for IPv6 addresses
>>>> 51ec7d3 ctdb-tools: Bracket IP addresses in onnode (for IPv6)
>>>> 9d4137d ctdb-tests: Extend regexp to match IPv6 addresses
>>>>
>>>
>>>
>>>> c9f3359 ctdb-tests: Try to handle IPv6 addresses for local daemons
>>>>
>>>
>>> In this patch, we cannot change the node IP addresses from 127.0.0.x to
>>> 127.0.234.x. Looks like socket wrapper does not like that, socket
>> wrapper
>>> expects addresses in 127.0.0.0/24 range. So here's a fixup to move node
>>> IPs away from 127.0.0.1.
>>>
>>> diff --git a/ctdb/tests/simple/scripts/local_daemons.bash
>>> b/ctdb/tests/simple/scripts/local_daemons.bash
>>> index 0131950..7d35a8f 100644
>>> --- a/ctdb/tests/simple/scripts/local_daemons.bash
>>> +++ b/ctdb/tests/simple/scripts/local_daemons.bash
>>> @@ -76,7 +76,8 @@ setup_ctdb ()
>>> echo "fc00:10::1:$(($i + $TEST_LOCAL_DAEMONS))/64 lo"
>>>>> "$public_addresses_all"
>>> fi
>>> else
>>> - echo 127.0.234.$i >>"$CTDB_NODES"
>>> + j=$(( $i + 10))
>>> + echo 127.0.0.$j >>"$CTDB_NODES"
>>> # 2 public addresses on most nodes, just to make things
>>> interesting.
>>> if [ $(($i - 1)) -ne $no_public_ips ] ; then
>>> echo "192.168.234.$i/24 lo" >>"$public_addresses_all"
>>
>> Maybe also the ipv6 socket_wrapper range:
>>
>> Samba uses this:
>>
>> $ctx->{ipv6} = sprintf("fd00:0000:0000:0000:0000:0000:5357:5f%02x",
>> $swiface);
>>
>> metze
>>
>>
> I don't see any hard-coding of specific IPv6 range in socket_wrapper code.
> What am I missing?
#ifdef HAVE_IPV6
/*
* FD00::5357:5FXX
*/
static const struct in6_addr *swrap_ipv6(void)
{
static struct in6_addr v;
static int initialized;
int ret;
if (initialized) {
return &v;
}
initialized = 1;
ret = inet_pton(AF_INET6, "FD00::5357:5F00", &v);
if (ret <= 0) {
abort();
}
return &v;
}
metze
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