When __inet_inherit_port() is called on a tproxy connection the wrong locks are
held for the inet_bind_bucket it is added to. __inet_inherit_port() made an
implicit assumption that the listener's port number (and thus its bind bucket).
Unfortunately, if you're using the TPROXY target to redirect skbs to a
transparent proxy that assumption is not true anymore and things break.

This patch adds code to __inet_inherit_port() so that it can handle this case
by looking up or creating a new bind bucket for the child socket and updates
callers of __inet_inherit_port() to gracefully handle __inet_inherit_port()
failing.

Reported by and original patch from Stephen Buck <stephen.buck@exinda.com>.
See http://marc.info/?t=128169268200001&r=1&w=2 for the original discussion.
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Also, inline this function as the lookup_type is always a literal
and inlining removes branches performed at runtime.
Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Without tproxy redirections an incoming SYN kicks out conflicting
TIME_WAIT sockets, in order to handle clients that reuse ports
within the TIME_WAIT period.

The same mechanism didn't work in case TProxy is involved in finding
the proper socket, as the time_wait processing code looked up the
listening socket assuming that the listener addr/port matches those
of the established connection.

This is not the case with TProxy as the listener addr/port is possibly
changed with the tproxy rule.
Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Lists were initialized after the module was registered.  Multiple ipvsadm
processes at module load triggered a race condition that resulted in a null
pointer dereference in do_ip_vs_get_ctl(). As a result, __ip_vs_mutex
was left locked preventing all further ipvsadm commands.
Signed-off-by: Eduardo J. Blanco <ejblanco@google.com>
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>

This patch allows to listen to events that inform about
expectations destroyed.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

The ebt_ip6.h and ebt_nflog.h headers are not not known to Kbuild and
therefore not installed by make headers_install.  Fix that up.
Signed-off-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Fix netfilter kconfig unmet dependencies warning & spell out
"compatible" while there.

warning: (IP_NF_TARGET_TTL && NET && INET && NETFILTER && IP_NF_IPTABLES && NETFILTER_ADVANCED || IP6_NF_TARGET_HL && NET && INET && IPV6 && NETFILTER && IP6_NF_IPTABLES && NETFILTER_ADVANCED) selects NETFILTER_XT_TARGET_HL which has unmet direct dependencies ((IP_NF_MANGLE || IP6_NF_MANGLE) && NETFILTER_ADVANCED)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

ip_vs_dbg_callid() and IP_VS_DEBUG_CALLID() are only needed
it CONFIG_IP_VS_DEBUG is defined.

This resolves the following build warning when CONFIG_IP_VS_DEBUG is
not defined.

net/netfilter/ipvs/ip_vs_pe_sip.c:11: warning: 'ip_vs_dbg_callid' defined but not used
Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

Unification of struct *_error_target was forgotten in
v2.6.16-1689-g1e30a014.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

Many of the used macros are just there for userspace compatibility.
Substitute the in-kernel code to directly use the terminal macro
and stuff the defines into #ifndef __KERNEL__ sections.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

Forgot to add xt_log.h in commit a8defca0 (netfilter: ipt_LOG:
add bufferisation to call printk() once)
Signed-off-by: Patrick McHardy <kaber@trash.net>

Since we register nf hooks, matches and targets in order, we'd better
unregister them in the reverse order.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Remove duplicated include.
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>

ipt_LOG & ip6t_LOG use lot of calls to printk() and use a lock in a hope
several cpus wont mix their output in syslog.

printk() being very expensive [1], its better to call it once, on a
prebuilt and complete line. Also, with mixed IPv4 and IPv6 trafic,
separate IPv4/IPv6 locks dont avoid garbage.

I used an allocation of a 1024 bytes structure, sort of seq_printf() but
with a fixed size limit.
Use a static buffer if dynamic allocation failed.

Emit a once time alert if buffer size happens to be too short.

[1]: printk() has various features like printk_delay()...
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

The functions nf_nat_proto_find_get and nf_nat_proto_put are
only used internally in nf_nat_core. This might break some out
of tree NAT module.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Add the SIP callid as a key for persistence.

This allows multiple connections from the same IP address to be
differentiated on the basis of the callid.

When used in conjunction with the persistence mask, it allows connections
from different  IP addresses to be aggregated on the basis of the callid.

It is envisaged that a persistence mask of 0.0.0.0 will be a useful
setting.  That is, ignore the source IP address when checking for
persistence.

It is envisaged that this option will be used in conjunction with
one-packet scheduling.

This only works with UDP and cannot be made to work with TCP
within the current framework.
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

Fall back to normal persistence handling if the persistence
engine fails to recognise a packet.

This way, at least the packet will go somewhere.

It is envisaged that iptables could be used to block packets
such if this is not desired although nf_conntrack_sip would
likely need to be enhanced first.
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

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 is based heavily on the scheduler management code
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>

Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

In general NULL arguments aren't passed by the few callers that exist,
so don't test for them.

The exception is to make passing NULL to ip_vs_unbind_scheduler() a noop.
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

This simplifies caller logic sightly.
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

Compact ip_vs_sched_persist() by setting up parameters
and calling functions once.
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

This patch adds the basic infrastructure to support user-space
expectation helpers via ctnetlink and the netfilter queuing
infrastructure NFQUEUE. Basically, this patch:

* adds NF_CT_EXPECT_USERSPACE flag to identify user-space
  created expectations. I have also added a sanity check in
  __nf_ct_expect_check() to avoid that kernel-space helpers
  may create an expectation if the master conntrack has no
  helper assigned.
* adds some branches to check if the master conntrack helper
  exists, otherwise we skip the code that refers to kernel-space
  helper such as the local expectation list and the expectation
  policy.
* allows to set the timeout for user-space expectations with
  no helper assigned.
* a list of expectations created from user-space that depends
  on ctnetlink (if this module is removed, they are deleted).
* includes USERSPACE in the /proc output for expectations
  that have been created by a user-space helper.

This patch also modifies ctnetlink to skip including the helper
name in the Netlink messages if no kernel-space helper is set
(since no user-space expectation has not kernel-space kernel
assigned).

You can access an example user-space FTP conntrack helper at:
http://people.netfilter.org/pablo/userspace-conntrack-helpers/nf-ftp-helper-userspace-POC.tar.bzSigned-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

With this patch, you can specify the expectation flags for user-space
created expectations.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

This patch adds the missing validation of the CTA_EXPECT_ZONE
attribute in the ctnetlink code.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

This patch improves the situation in which the expectation table is
full for conntrack NAT helpers. Basically, we give up if we don't
find a place in the table instead of looping over nf_ct_expect_related()
with a different port (we should only do this if it returns -EBUSY, for
-EMFILE or -ESHUTDOWN I think that it's better to skip this).
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

	Change the usage of svc usecnt during command execution:

- we check if svc is registered but we do not need to hold usecnt
reference while under __ip_vs_mutex, only the packet handling needs
it during scheduling

- change __ip_vs_service_get to __ip_vs_service_find and
__ip_vs_svc_fwm_get to __ip_vs_svc_fwm_find because now caller
will increase svc->usecnt

- put common code that calls update_service in __ip_vs_update_dest

- put common code in ip_vs_unlink_service() and use it to unregister
the service

- add comment that svc should not be accessed after ip_vs_del_service
anymore

- all IP_VS_WAIT_WHILE calls are now unified: usecnt > 0

- Properly log the app ports

	As result, some problems are fixed:

- possible use-after-free of svc in ip_vs_genl_set_cmd after
ip_vs_del_service because our usecnt reference does not guarantee that
svc is not freed on refcnt==0, eg. when no dests are moved to trash

- possible usecnt leak in do_ip_vs_set_ctl after ip_vs_del_service
when the service is not freed now, for example, when some
destionations are moved into trash and svc->refcnt remains above 0.
It is harmless because svc is not in hash anymore.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>

Since we don't change the tuple in the original direction, we can save it
in ct->tuplehash[IP_CT_DIR_REPLY].hnode.pprev for __nf_conntrack_confirm()
use.

__hash_conntrack() is split into two steps: hash_conntrack_raw() is used
to get the raw hash, and __hash_bucket() is used to get the bucket id.

In SYN-flood case, early_drop() doesn't need to recompute the hash again.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

	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>