Pushing original fragments through causes several problems. For example
for matching, frags may not be matched correctly. Take following
example:
<example>
On HOSTA do:
ip6tables -I INPUT -p icmpv6 -j DROP
ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT
and on HOSTB you do:
ping6 HOSTA -s2000 (MTU is 1500)
Incoming echo requests will be filtered out on HOSTA. This issue does
not occur with smaller packets than MTU (where fragmentation does not happen)
</example>
As was discussed previously, the only correct solution seems to be to use
reassembled skb instead of separete frags. Doing this has positive side
effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams
dances in ipvs and conntrack can be removed.
Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c
entirely and use code in net/ipv6/reassembly.c instead.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
This is another batch containing Netfilter/IPVS updates for your net-next
tree, they are:
* Six patches to make the ipt_CLUSTERIP target support netnamespace,
from Gao feng.
* Two cleanups for the nf_conntrack_acct infrastructure, introducing
a new structure to encapsulate conntrack counters, from Holger
Eitzenberger.
* Fix missing verdict in SCTP support for IPVS, from Daniel Borkmann.
* Skip checksum recalculation in SCTP support for IPVS, also from
Daniel Borkmann.
* Fix behavioural change in xt_socket after IP early demux, from
Florian Westphal.
* Fix bogus large memory allocation in the bitmap port set type in ipset,
from Jozsef Kadlecsik.
* Fix possible compilation issues in the hash netnet set type in ipset,
also from Jozsef Kadlecsik.
* Define constants to identify netlink callback data in ipset dumps,
again from Jozsef Kadlecsik.
* Use sock_gen_put() in xt_socket to replace xt_socket_put_sk,
from Eric Dumazet.
* Improvements for the SH scheduler in IPVS, from Alexander Frolkin.
* Remove extra delay due to unneeded rcu barrier in IPVS net namespace
cleanup path, from Julian Anastasov.
* Save some cycles in ip6t_REJECT by skipping checksum validation in
packets leaving from our stack, from Stanislav Fomichev.
* Fix IPVS_CMD_ATTR_MAX definition in IPVS, larger that required, from
Julian Anastasov.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Unlike UDP or TCP, we do not take the pseudo-header into
account in SCTP checksums. So in case port mapping is the
very same, we do not need to recalculate the whole SCTP
checksum in software, which is very expensive.
Also, similarly as in TCP, take into account when a private
helper mangled the packet. In that case, we also need to
recalculate the checksum even if ports might be same.
Thanks for feedback regarding skb->ip_summed checks from
Julian Anastasov; here's a discussion on these checks for
snat and dnat:
* For snat_handler(), we can see CHECKSUM_PARTIAL from
virtual devices, and from LOCAL_OUT, otherwise it
should be CHECKSUM_UNNECESSARY. In general, in snat it
is more complex. skb contains the original route and
ip_vs_route_me_harder() can change the route after
snat_handler. So, for locally generated replies from
local server we can not preserve the CHECKSUM_PARTIAL
mode. It is an chicken or egg dilemma: snat_handler
needs the device after rerouting (to check for
NETIF_F_SCTP_CSUM), while ip_route_me_harder() wants
the snat_handler() to put the new saddr for proper
rerouting.
* For dnat_handler(), we should not see CHECKSUM_COMPLETE
for SCTP, in fact the small set of drivers that support
SCTP offloading return CHECKSUM_UNNECESSARY on correctly
received SCTP csum. We can see CHECKSUM_PARTIAL from
local stack or received from virtual drivers. The idea is
that SCTP decides to avoid csum calculation if hardware
supports offloading. IPVS can change the device after
rerouting to real server but we can preserve the
CHECKSUM_PARTIAL mode if the new device supports
offloading too. This works because skb dst is changed
before dnat_handler and we see the new device. So, checks
in the 'if' part will decide whether it is ok to keep
CHECKSUM_PARTIAL for the output. If the packet was with
CHECKSUM_NONE, hence we deal with unknown checksum. As we
recalculate the sum for IP header in all cases, it should
be safe to use CHECKSUM_UNNECESSARY. We can forward wrong
checksum in this case (without cp->app). In case of
CHECKSUM_UNNECESSARY, the csum was valid on receive.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
If skb_header_pointer() fails, we need to assign a verdict, that is
NF_DROP in this case, otherwise, we would leave the verdict from
conn_schedule() uninitialized when returning.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Improve the SH fallback realserver selection strategy.
With sh and sh-fallback, if a realserver is down, this attempts to
distribute the traffic that would have gone to that server evenly
among the remaining servers.
Signed-off-by: Alexander Frolkin <avf@eldamar.org.uk>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
commit 578bc3ef1e ("ipvs: reorganize dest trash") added
rcu_barrier() on cleanup to wait dest users and schedulers
like LBLC and LBLCR to put their last dest reference.
Using rcu_barrier with many namespaces is problematic.
Trying to fix it by freeing dest with kfree_rcu is not
a solution, RCU callbacks can run in parallel and execution
order is random.
Fix it by creating new function ip_vs_dest_put_and_free()
which is heavier than ip_vs_dest_put(). We will use it just
for schedulers like LBLC, LBLCR that can delay their dest
release.
By default, dests reference is above 0 if they are present in
service and it is 0 when deleted but still in trash list.
Change the dest trash code to use ip_vs_dest_put_and_free(),
so that refcnt -1 can be used for freeing. As result,
such checks remain in slow path and the rcu_barrier() from
netns cleanup can be removed.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Pass the hook ops to the hookfn to allow for generic hook
functions. This change is required by nf_tables.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
The following patchset contains Netfilter/IPVS fixes for your net
tree, they are:
* Fix BUG_ON splat due to malformed TCP packets seen by synproxy, from
Patrick McHardy.
* Fix possible weight overflow in lblc and lblcr schedulers due to
32-bits arithmetics, from Simon Kirby.
* Fix possible memory access race in the lblc and lblcr schedulers,
introduced when it was converted to use RCU, two patches from
Julian Anastasov.
* Fix hard dependency on CPU 0 when reading per-cpu stats in the
rate estimator, from Julian Anastasov.
* Fix race that may lead to object use after release, when invoking
ipvsadm -C && ipvsadm -R, introduced when adding RCU, from Julian
Anastasov.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.
For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.
Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When reading percpu stats we need to properly reset
the sum when CPU 0 is not present in the possible mask.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
commit c5549571f9 ("ipvs: convert lblcr scheduler to rcu")
allows RCU readers to use dest after calling ip_vs_dest_put().
In the corner case it can race with ip_vs_dest_trash_expire()
which can release the dest while it is being returned to the
RCU readers as scheduling result.
To fix the problem do not allow e->dest to be replaced and
defer the ip_vs_dest_put() call by using RCU callback. Now
e->dest does not need to be RCU pointer.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
commit c2a4ffb70e ("ipvs: convert lblc scheduler to rcu")
allows RCU readers to use dest after calling ip_vs_dest_put().
In the corner case it can race with ip_vs_dest_trash_expire()
which can release the dest while it is being returned to the
RCU readers as scheduling result.
To fix the problem do not allow en->dest to be replaced and
defer the ip_vs_dest_put() call by using RCU callback. Now
en->dest does not need to be RCU pointer.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
commit 578bc3ef1e ("ipvs: reorganize dest trash") added
IP_VS_DEST_STATE_REMOVING flag and RCU callback named
ip_vs_dest_wait_readers() to keep dests and services after
removal for at least a RCU grace period. But we have the
following corner cases:
- we can not reuse the same dest if its service is removed
while IP_VS_DEST_STATE_REMOVING is still set because another dest
removal in the first grace period can not extend this period.
It can happen when ipvsadm -C && ipvsadm -R is used.
- dest->svc can be replaced but ip_vs_in_stats() and
ip_vs_out_stats() have no explicit read memory barriers
when accessing dest->svc. It can happen that dest->svc
was just freed (replaced) while we use it to update
the stats.
We solve the problems as follows:
- IP_VS_DEST_STATE_REMOVING is removed and we ensure a fixed
idle period for the dest (IP_VS_DEST_TRASH_PERIOD). idle_start
will remember when for first time after deletion we noticed
dest->refcnt=0. Later, the connections can grab a reference
while in RCU grace period but if refcnt becomes 0 we can
safely free the dest and its svc.
- dest->svc becomes RCU pointer. As result, we add explicit
RCU locking in ip_vs_in_stats() and ip_vs_out_stats().
- __ip_vs_unbind_svc is renamed to __ip_vs_svc_put(), it
now can free the service immediately or after a RCU grace
period. dest->svc is not set to NULL anymore.
As result, unlinked dests and their services are
freed always after IP_VS_DEST_TRASH_PERIOD period, unused
services are freed after a RCU grace period.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Schedulers such as lblc and lblcr require the weight to be as high as the
maximum number of active connections. In commit b552f7e3a9
("ipvs: unify the formula to estimate the overhead of processing
connections"), the consideration of inactconns and activeconns was cleaned
up to always count activeconns as 256 times more important than inactconns.
In cases where 3000 or more connections are expected, a weight of 3000 *
256 * 3000 connections overflows the 32-bit signed result used to determine
if rescheduling is required.
On amd64, this merely changes the multiply and comparison instructions to
64-bit. On x86, a 64-bit result is already present from imull, so only
a few more comparison instructions are emitted.
Signed-off-by: Simon Kirby <sim@hostway.ca>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Conflicts:
net/netfilter/nf_conntrack_proto_tcp.c
The conflict had to do with overlapping changes dealing with
fixing the use of an "s32" to hold the value returned by
NAT_OFFSET().
Pablo Neira Ayuso says:
====================
The following batch contains Netfilter/IPVS updates for your net-next tree.
More specifically, they are:
* Trivial typo fix in xt_addrtype, from Phil Oester.
* Remove net_ratelimit in the conntrack logging for consistency with other
logging subsystem, from Patrick McHardy.
* Remove unneeded includes from the recently added xt_connlabel support, from
Florian Westphal.
* Allow to update conntracks via nfqueue, don't need NFQA_CFG_F_CONNTRACK for
this, from Florian Westphal.
* Remove tproxy core, now that we have socket early demux, from Florian
Westphal.
* A couple of patches to refactor conntrack event reporting to save a good
bunch of lines, from Florian Westphal.
* Fix missing locking in NAT sequence adjustment, it did not manifested in
any known bug so far, from Patrick McHardy.
* Change sequence number adjustment variable to 32 bits, to delay the
possible early overflow in long standing connections, also from Patrick.
* Comestic cleanups for IPVS, from Dragos Foianu.
* Fix possible null dereference in IPVS in the SH scheduler, from Daniel
Borkmann.
* Allow to attach conntrack expectations via nfqueue. Before this patch, you
had to use ctnetlink instead, thus, we save the conntrack lookup.
* Export xt_rpfilter and xt_HMARK header files, from Nicolas Dichtel.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_header_pointer could return NULL, so check for it as we do it
everywhere else in ipvs code. This fixes a coverity warning.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
This patch consolidates the SCTP checksum calculation code from various
places to a single new function, sctp_compute_cksum(skb, offset).
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/freescale/fec_main.c
drivers/net/ethernet/renesas/sh_eth.c
net/ipv4/gre.c
The GRE conflict is between a bug fix (kfree_skb --> kfree_skb_list)
and the splitting of the gre.c code into seperate files.
The FEC conflict was two sets of changes adding ethtool support code
in an "!CONFIG_M5272" CPP protected block.
Finally the sh_eth.c conflict was between one commit add bits set
in the .eesr_err_check mask whilst another commit removed the
.tx_error_check member and assignments.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add sync_persist_mode flag to reduce sync traffic
by syncing only persistent templates.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Tested-by: Aleksey Chudov <aleksey.chudov@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
By default the SH scheduler rejects connections that are hashed onto a
realserver of weight 0. This patch adds a flag to make SH choose a
different realserver in this case, instead of rejecting the connection.
The patch also adds a flag to make SH include the source port (TCP, UDP,
SCTP) in the hash as well as the source address. This basically allows
for deterministic round-robin load balancing (i.e., where any director
in a cluster of directors with identical config will send the same
packet the same way).
The flags are service flags (IP_VS_SVC_F_SCHED*) so that these options
can be set per service. They are set using a new option to ipvsadm.
Signed-off-by: Alexander Frolkin <avf@eldamar.org.uk>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Drop SCTP connections under load (dropentry context) depending
on the protocol state, just like for TCP: INIT conns are
dropped immediately, established are dropped randomly while
connections in progress or shutdown are skipped.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Convert the SCTP state table, so that it is more readable.
Change the states to be according to the diagram in RFC 2960
and add more states suitable for middle box. Still, such
change in states adds incompatibility if systems in sync
setup include this change and others do not include it.
With this change we also have proper transitions in INPUT-ONLY
mode (DR/TUN) where we see packets only from client. Now
we should not switch to 10-second CLOSED state at a time
when we should stay in ESTABLISHED state.
The short names for states are because we have 16-char space
in ipvsadm and 11-char limit for the connection list format.
It is a sequence of the TCP implementation where the longest
state name is ESTABLISHED.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
This adds support for sloppy TCP and SCTP modes to IPVS.
When enabled (sysctls net.ipv4.vs.sloppy_tcp and
net.ipv4.vs.sloppy_sctp), allows IPVS to create connection state on any
packet, not just a TCP SYN (or SCTP INIT).
This allows connections to fail over from one IPVS director to another
mid-flight.
Signed-off-by: Alexander Frolkin <avf@eldamar.org.uk>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Before now the schedulers needed access only to IP
addresses and it was easy to get them from skb by
using ip_vs_fill_iph_addr_only.
New changes for the SH scheduler will need the protocol
and ports which is difficult to get from skb for the
IPv6 case. As we have all the data in the iph structure,
to avoid the same slow lookups provide the iph to schedulers.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
