ip_vs_protocol *pp is replaced by ip_vs_proto_data *pd in
function call in ip_vs_protocol struct i.e. :,
- timeout_change()
- state_transition()
ip_vs_protocol_timeout_change() got ipvs as param, due to above
and a upcoming patch - defence work
Most of this changes are triggered by Julians comment:
"tcp_timeout_change should work with the new struct ip_vs_proto_data
so that tcp_state_table will go to pd->state_table
and set_tcp_state will get pd instead of pp"
*v3
Mostly comments from Julian
The pp -> pd conversion should start from functions like
ip_vs_out() that use pp = ip_vs_proto_get(iph.protocol),
now they should use ip_vs_proto_data_get(net, iph.protocol).
conn_in_get() and conn_out_get() unused param *pp, removed.
*v4
ip_vs_protocol_timeout_change() walk the proto_data path.
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
In this phase (one), all local vars will be moved to ipvs struct.
Remaining work, add param struct net *net to a couple of
functions that is common for all protos and use all
ip_vs_proto_data
*v3
Removed unused function as sugested by Simon
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Add support for protocol data per name-space.
in struct ip_vs_protocol, appcnt will be removed when all protos
are modified for network name-space.
This patch causes warnings of unused functions, they will be used
when next patch will be applied.
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Services hash tables got netns ptr a hash arg,
While Real Servers (rs) has been moved to ipvs struct.
Two new inline functions added to get net ptr from skb.
Since ip_vs is called from different contexts there is two
places to dig for the net ptr skb->dev or skb->sk
this is handled in skb_net() and skb_sknet()
Global functions, ip_vs_service_get() ip_vs_lookup_real_service()
etc have got struct net *net as first param.
If possible get net ptr skb etc,
- if not &init_net is used at this early stage of patching.
ip_vs_ctl.c procfs not ready for netns yet.
*v3
Comments by Julian
- __ip_vs_service_find and __ip_vs_svc_fwm_find are fast path,
net_eq(svc->net, net) so the check is at the end now.
- net = skb_net(skb) in ip_vs_out moved after check for skb_dst.
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Preparation for network name-space init, in this stage
some empty functions exists.
In most files there is a check if it is root ns i.e. init_net
if (!net_eq(net, &init_net))
return ...
this will be removed by the last patch, when enabling name-space.
*v3
ip_vs_conn.c merge error corrected.
net_ipvs #ifdef removed as sugested by Jan Engelhardt
[ horms@verge.net.au: Removed whitespace-change-only hunks ]
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
This patch adds a sysclt net.ipv4.vs.sync_version
that can be used to send sync msg in version 0 or 1 format.
sync_version value is logical,
Value 1 (default) New version
0 Plain old version
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Enable sending and removal of version 0 sending
Affected functions,
ip_vs_sync_buff_create()
ip_vs_sync_conn()
ip_vs_core.c removal of IPv4 check.
*v5
Just check cp->pe_data_len in ip_vs_sync_conn
Check if padding needed before adding a new sync_conn
to the buffer, i.e. avoid sending padding at the end.
*v4
moved sanity check and pe_name_len after sloop.
use cp->pe instead of cp->dest->svc->pe
real length in each sync_conn, not padded length
however total size of a sync_msg includes padding.
*v3
Sending ip_vs_sync_conn_options in network order.
Sending Templates for ONE_PACKET conn.
Renaming of ip_vs_sync_mesg to ip_vs_sync_mesg_v0
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Functionality improvements
* flags changed from 16 to 32 bits
* fwmark added (32 bits)
* timeout in sec. added (32 bits)
* pe data added (Variable length)
* IPv6 capabilities (3x16 bytes for addr.)
* Version and type in every conn msg.
ip_vs_process_message() now handles Version 1 messages
and will call ip_vs_process_message_v0() for version 0 messages.
ip_vs_proc_conn() is common for both version, and handles the update of
connection hash.
ip_vs_conn_fill_param_sync() - Version 1 messages only
ip_vs_conn_fill_param_sync_v0() - Version 0 messages only
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
One struct will have fwmark added:
* ip_vs_conn
ip_vs_conn_new() and ip_vs_find_dest()
will have an extra param - fwmark
The effects of that, is in this patch.
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
The dest of a connection may not exist if it has been created as the result
of connection synchronisation. But in order for connection entries for
templates with persistence engine data created through connection
synchronisation to be valid access to the persistence engine pointer is
required. So add the persistence engine to the connection itself.
Signed-off-by: Simon Horman <horms@verge.net.au>
As skb->protocol is not valid in LOCAL_OUT add
parameter for address family in packet debugging functions.
Even if ports are not present in AH and ESP change them to
use ip_vs_tcpudp_debug_packet to show at least valid addresses
as before. This patch removes the last user of skb->protocol
in IPVS.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
This patch deals with local real servers:
- Add support for DNAT to local address (different real server port).
It needs ip_vs_out hook in LOCAL_OUT for both families because
skb->protocol is not set for locally generated packets and can not
be used to set 'af'.
- Skip packets in ip_vs_in marked with skb->ipvs_property because
ip_vs_out processing can be executed in LOCAL_OUT but we still
have the conn_out_get check in ip_vs_in.
- Ignore packets with inet->nodefrag from local stack
- Require skb_dst(skb) != NULL because we use it to get struct net
- Add support for changing the route to local IPv4 stack after DNAT
depending on the source address type. Local client sets output
route and the remote client sets input route. It looks like
IPv6 does not need such rerouting because the replies use
addresses from initial incoming header, not from skb route.
- All transmitters now have strict checks for the destination
address type: redirect from non-local address to local real
server requires NAT method, local address can not be used as
source address when talking to remote real server.
- Now LOCALNODE is not set explicitly as forwarding
method in real server to allow the connections to provide
correct forwarding method to the backup server. Not sure if
this breaks tools that expect to see 'Local' real server type.
If needed, this can be supported with new flag IP_VS_DEST_F_LOCAL.
Now it should be possible connections in backup that lost
their fwmark information during sync to be forwarded properly
to their daddr, even if it is local address in the backup server.
By this way backup could be used as real server for DR or TUN,
for NAT there are some restrictions because tuple collisions
in conntracks can create problems for the traffic.
- Call ip_vs_dst_reset when destination is updated in case
some real server IP type is changed between local and remote.
[ horms@verge.net.au: removed trailing whitespace ]
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
This patch is needed to avoid scheduling of
packets from local real server when we add ip_vs_in
in LOCAL_OUT hook to support local client.
Currently, when ip_vs_in can not find existing
connection it tries to create new one by calling ip_vs_schedule.
The default indication from ip_vs_schedule was if
connection was scheduled to real server. If real server is
not available we try to use the bypass forwarding method
or to send ICMP error. But in some cases we do not want to use
the bypass feature. So, add flag 'ignored' to indicate if
the scheduler ignores this packet.
Make sure we do not create new connections from replies.
We can hit this problem for persistent services and local real
server when ip_vs_in is added to LOCAL_OUT hook to handle
local clients.
Also, make sure ip_vs_schedule ignores SYN packets
for Active FTP DATA from local real server. The FTP DATA
connection should be created on SYN+ACK from client to assign
correct connection daddr.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Change skb->ipvs_property semantic. This is preparation
to support ip_vs_out processing in LOCAL_OUT. ipvs_property=1
will be used to avoid expensive lookups for traffic sent by
transmitters. Now when conntrack support is not used we call
ip_vs_notrack method to avoid problems in OUTPUT and
POST_ROUTING hooks instead of exiting POST_ROUTING as before.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Avoid full checksum calculation for apps that can provide
info whether csum was broken after payload mangling. For now only
ip_vs_ftp mangles payload and it updates the csum, so the full
recalculation is avoided for all packets.
Add CHECKSUM_UNNECESSARY for snat_handler (TCP and UDP).
It is needed to support SNAT from local address for the case
when csum is fully recalculated.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
IPv6 encapsulation uses a bad source address for the tunnel.
i.e. VIP will be used as local-addr and encap. dst addr.
Decapsulation will not accept this.
Example
LVS (eth1 2003::2:0:1/96, VIP 2003::2:0:100)
(eth0 2003::1:0:1/96)
RS (ethX 2003::1:0:5/96)
tcpdump
2003::2:0:100 > 2003::1:0:5: IP6 (hlim 63, next-header TCP (6) payload length: 40) 2003::3:0:10.50991 > 2003::2:0:100.http: Flags [S], cksum 0x7312 (correct), seq 3006460279, win 5760, options [mss 1440,sackOK,TS val 1904932 ecr 0,nop,wscale 3], length 0
In Linux IPv6 impl. you can't have a tunnel with an any cast address
receiving packets (I have not tried to interpret RFC 2473)
To have receive capabilities the tunnel must have:
- Local address set as multicast addr or an unicast addr
- Remote address set as an unicast addr.
- Loop back addres or Link local address are not allowed.
This causes us to setup a tunnel in the Real Server with the
LVS as the remote address, here you can't use the VIP address since it's
used inside the tunnel.
Solution
Use outgoing interface IPv6 address (match against the destination).
i.e. use ip6_route_output() to look up the route cache and
then use ipv6_dev_get_saddr(...) to set the source address of the
encapsulated packet.
Additionally, cache the results in new destination
fields: dst_cookie and dst_saddr and properly check the
returned dst from ip6_route_output. We now add xfrm_lookup
call only for the tunneling method where the source address
is a local one.
Signed-off-by:Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Allow the persistence engine of a virtual service to be set, edited
and unset.
This feature only works with the netlink user-space interface.
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>
This shouldn't break compatibility with userspace as the new data
is at the end of the line.
I have confirmed that this doesn't break ipvsadm, the main (only?)
user-space user of this data.
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>
Add new sysctl flag "snat_reroute". Recent kernels use
ip_route_me_harder() to route LVS-NAT responses properly by
VIP when there are multiple paths to client. But setups
that do not have alternative default routes can skip this
routing lookup by using snat_reroute=0.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Add more code to IPVS to work with Netfilter connection
tracking and fix some problems.
- Allow IPVS to be compiled without connection tracking as in
2.6.35 and before. This can avoid keeping conntracks for all
IPVS connections because this costs memory. ip_vs_ftp still
depends on connection tracking and NAT as implemented for 2.6.36.
- Add sysctl var "conntrack" to enable connection tracking for
all IPVS connections. For loaded IPVS directors it needs
tuning of nf_conntrack_max limit.
- Add IP_VS_CONN_F_NFCT connection flag to request the connection
to use connection tracking. This allows user space to provide this
flag, for example, in dest->conn_flags. This can be useful to
request connection tracking per real server instead of forcing it
for all connections with the "conntrack" sysctl. This flag is
set currently only by ip_vs_ftp and of course by "conntrack" sysctl.
- Add ip_vs_nfct.c file to hold all connection tracking code,
by this way main code should not depend of netfilter conntrack
support.
- Return back the ip_vs_post_routing handler as in 2.6.35 and use
skb->ipvs_property=1 to allow IPVS to work without connection
tracking
Connection tracking:
- most of the code is already in 2.6.36-rc
- alter conntrack reply tuple for LVS-NAT connections when first packet
from client is forwarded and conntrack state is NEW or RELATED.
Additionally, alter reply for RELATED connections from real server,
again for packet in original direction.
- add IP_VS_XMIT_TUNNEL to confirm conntrack (without altering
reply) for LVS-TUN early because we want to call nf_reset. It is
needed because we add IPIP header and the original conntrack
should be preserved, not destroyed. The transmitted IPIP packets
can reuse same conntrack, so we do not set skb->ipvs_property.
- try to destroy conntrack when the IPVS connection is destroyed.
It is not fatal if conntrack disappears before that, it depends
on the used timers.
Fix problems from long time:
- add skb->ip_summed = CHECKSUM_NONE for the LVS-TUN transmitters
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Patrick McHardy <kaber@trash.net>
- the sync protocol supports 16 bits only, so bits 0..15 should be
used only for flags that should go to backup server, bits 16 and
above should be allocated for flags not sent to backup.
- use IP_VS_CONN_F_DEST_MASK as mask of connection flags in
destination that can be changed by user space
- allow IP_VS_CONN_F_ONE_PACKET to be set in destination
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Patrick McHardy <kaber@trash.net>
- Do not create expectation when forwarding the PORT
command to avoid blocking the connection. The problem is that
nf_conntrack_ftp.c:help() tries to create the same expectation later in
POST_ROUTING and drops the packet with "dropping packet" message after
failure in nf_ct_expect_related.
- Change ip_vs_update_conntrack to alter the conntrack
for related connections from real server. If we do not alter the reply in
this direction the next packet from client sent to vport 20 comes as NEW
connection. We alter it but may be some collision happens for both
conntracks and the second conntrack gets destroyed immediately. The
connection stucks too.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This removes duplicate code by providing a default implementation
which is used by 3 of the 4 modules that provide these call.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Use nf_conntrack/nf_nat code to do the packet mangling and the TCP
sequence adjusting. The function 'ip_vs_skb_replace' is now dead
code, so it is removed.
To SNAT FTP, use something like:
% iptables -t nat -A POSTROUTING -m ipvs --vaddr 192.168.100.30/32 \
--vport 21 -j SNAT --to-source 192.168.10.10
and for the data connections in passive mode:
% iptables -t nat -A POSTROUTING -m ipvs --vaddr 192.168.100.30/32 \
--vportctl 21 -j SNAT --to-source 192.168.10.10
using '-m state --state RELATED' would also works.
Make sure the kernel modules ip_vs_ftp, nf_conntrack_ftp, and
nf_nat_ftp are loaded.
[ up-port and minor fixes by Simon Horman <horms@verge.net.au> ]
Signed-off-by: Hannes Eder <heder@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Enhance IPVS to load balance SCTP transport protocol packets. This is done
based on the SCTP rfc 4960. All possible control chunks have been taken
care. The state machine used in this code looks some what lengthy. I tried
to make the state machine easy to understand.
Signed-off-by: Venkata Mohan Reddy Koppula <mohanreddykv@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>
I was very frustrated about the fact that I have to recompile the kernel
to change the hash size. So, I created this patch.
If IPVS is built-in you can append ip_vs.conn_tab_bits=?? to kernel
command line, or, if you built IPVS as modules, you can add
options ip_vs conn_tab_bits=??.
To keep everything backward compatible, you still can select the size at
compile time, and that will be used as default.
It has been about a year since this patch was originally posted
and subsequently dropped on the basis of insufficient test data.
Mark Bergsma has provided the following test results which seem
to strongly support the need for larger hash table sizes:
We do however run into the same problem with the default setting (212 =
4096 entries), as most of our LVS balancers handle around a million
connections/SLAB entries at any point in time (around 100-150 kpps
load). With only 4096 hash table entries this implies that each entry
consists of a linked list of 256 connections *on average*.
To provide some statistics, I did an oprofile run on an 2.6.31 kernel,
with both the default 4096 table size, and the same kernel recompiled
with IP_VS_CONN_TAB_BITS set to 18 (218 = 262144 entries). I built a
quick test setup with a part of Wikimedia/Wikipedia's live traffic
mirrored by the switch to the test host.
With the default setting, at ~ 120 kpps packet load we saw a typical %si
CPU usage of around 30-35%, and oprofile reported a hot spot in
ip_vs_conn_in_get:
samples % image name app name
symbol name
1719761 42.3741 ip_vs.ko ip_vs.ko ip_vs_conn_in_get
302577 7.4554 bnx2 bnx2 /bnx2
181984 4.4840 vmlinux vmlinux __ticket_spin_lock
128636 3.1695 vmlinux vmlinux ip_route_input
74345 1.8318 ip_vs.ko ip_vs.ko ip_vs_conn_out_get
68482 1.6874 vmlinux vmlinux mwait_idle
After loading the recompiled kernel with 218 entries, %si CPU usage
dropped in half to around 12-18%, and oprofile looks much healthier,
with only 7% spent in ip_vs_conn_in_get:
samples % image name app name
symbol name
265641 14.4616 bnx2 bnx2 /bnx2
143251 7.7986 vmlinux vmlinux __ticket_spin_lock
140661 7.6576 ip_vs.ko ip_vs.ko ip_vs_conn_in_get
94364 5.1372 vmlinux vmlinux mwait_idle
86267 4.6964 vmlinux vmlinux ip_route_input
[ horms@verge.net.au: trivial up-port and minor style fixes ]
Signed-off-by: Catalin(ux) M. BOIE <catab@embedromix.ro>
Cc: Mark Bergsma <mark@wikimedia.org>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.
struct something
{
becomes :
struct something {
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
String literals are constant, and usually, we can also tag the array
of pointers const too, moving it to the .rodata section.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since pr_err and friends are used instead of printk there is no point
in keeping IP_VS_ERR and friends. Furthermore make use of '__func__'
instead of hard coded function names.
Signed-off-by: Hannes Eder <heder@google.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Base versions handle constant folding now. For headers exposed to
userspace, we must only expose the __ prefixed versions.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The first argument to csum_partial is const void *
casts to char/u8 * are not necessary
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove the 'supports_ipv6' scheduler flag since all schedulers now
support IPv6.
Signed-off-by: Julius Volz <julius.volz@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u
can be replaced with %pI4
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
inet_iif() in inet_sock.h requires route.h. Since users of inet_iif()
usually require other route.h functionality anyway this patch moves
inet_iif() to route.h.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of duplicating the fields, integrate a user stats structure into
the kernel stats structure. This is more robust when the members are
changed, because they are now automatically kept in sync.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Reviewed-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Instead of checking the value in include/net/ip_vs.h, we can just
restrict the range in our Kconfig file. This will prevent values outside
of the range early.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Reviewed-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Adjust various debug outputs to use the new *_BUF macro variants for
correct output of v4/v6 addresses.
Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Convert functions for looking up destinations (real servers) to support
IPv6 services/dests.
Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Add xmit functions for IPv6. Also add the already needed __ip_vs_get_out_rt_v6()
to ip_vs_core.c. Bind the new xmit functions to v6 connections.
Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Extend functions for getting/creating connections and connection
templates for IPv6 support and fix the callers.
Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Extend protocol DNAT/SNAT and state handlers to work with IPv6. Also
change/introduce new checksumming helper functions for this.
Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Add 'af' arguments to conn_schedule(), conn_in_get(), conn_out_get() and
csum_check() function pointers in struct ip_vs_protocol. Extend the
respective functions for TCP, UDP, AH and ESP and adjust the callers.
The changes in the callers need to be somewhat extensive, since they now
need to pass a filled out struct ip_vs_iphdr * to the modified functions
instead of a struct iphdr *.
Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>