Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
A final pull request, I know it's very late but this time I think it's worth a
bit of rush.
The following patchset contains Netfilter/nf_tables updates for net-next, more
specifically concatenation support and dynamic stateful expression
instantiation.
This also comes with a couple of small patches. One to fix the ebtables.h
userspace header and another to get rid of an obsolete example file in tree
that describes a nf_tables expression.
This time, I decided to paste the original descriptions. This will result in a
rather large commit description, but I think these bytes to keep.
Patrick McHardy says:
====================
netfilter: nf_tables: concatenation support
The following patches add support for concatenations, which allow multi
dimensional exact matches in O(1).
The basic idea is to split the data registers, currently consisting of
4 registers of 16 bytes each, into smaller units, 16 registers of 4
bytes each, and making sure each register store always leaves the
full 32 bit in a well defined state, meaning smaller stores will
zero the remaining bits.
Based on that, we can load multiple adjacent registers with different
values, thereby building a concatenated bigger value, and use that
value for set lookups.
Sets are changed to use variable sized extensions for their key and
data values, removing the fixed limit of 16 bytes while saving memory
if less space is needed.
As a side effect, these patches will allow some nice optimizations in
the future, like using jhash2 in nft_hash, removing the masking in
nft_cmp_fast, optimized data comparison using 32 bit word size etc.
These are not done so far however.
The patches are split up as follows:
* the first five patches add length validation to register loads and
stores to make sure we stay within bounds and prepare the validation
functions for the new addressing mode
* the next patches prepare for changing to 32 bit addressing by
introducing a struct nft_regs, which holds the verdict register as
well as the data registers. The verdict members are moved to a new
struct nft_verdict to allow to pull struct nft_data out of the stack.
* the next patches contain preparatory conversions of expressions and
sets to use 32 bit addressing
* the next patch introduces so far unused register conversion helpers
for parsing and dumping register numbers over netlink
* following is the real conversion to 32 bit addressing, consisting of
replacing struct nft_data in struct nft_regs by an array of u32s and
actually translating and validating the new register numbers.
* the final two patches add support for variable sized data items and
variable sized keys / data in set elements
The patches have been verified to work correctly with nft binaries using
both old and new addressing.
====================
Patrick McHardy says:
====================
netfilter: nf_tables: dynamic stateful expression instantiation
The following patches are the grand finale of my nf_tables set work,
using all the building blocks put in place by the previous patches
to support something like iptables hashlimit, but a lot more powerful.
Sets are extended to allow attaching expressions to set elements.
The dynset expression dynamically instantiates these expressions
based on a template when creating new set elements and evaluates
them for all new or updated set members.
In combination with concatenations this effectively creates state
tables for arbitrary combinations of keys, using the existing
expression types to maintain that state. Regular set GC takes care
of purging expired states.
We currently support two different stateful expressions, counter
and limit. Using limit as a template we can express the functionality
of hashlimit, but completely unrestricted in the combination of keys.
Using counter we can perform accounting for arbitrary flows.
The following examples from patch 5/5 show some possibilities.
Userspace syntax is still WIP, especially the listing of state
tables will most likely be seperated from normal set listings
and use a more structured format:
1. Limit the rate of new SSH connections per host, similar to iptables
hashlimit:
flow ip saddr timeout 60s \
limit 10/second \
accept
2. Account network traffic between each set of /24 networks:
flow ip saddr & 255.255.255.0 . ip daddr & 255.255.255.0 \
counter
3. Account traffic to each host per user:
flow skuid . ip daddr \
counter
4. Account traffic for each combination of source address and TCP flags:
flow ip saddr . tcp flags \
counter
The resulting set content after a Xmas-scan look like this:
{
192.168.122.1 . fin | psh | urg : counter packets 1001 bytes 40040,
192.168.122.1 . ack : counter packets 74 bytes 3848,
192.168.122.1 . psh | ack : counter packets 35 bytes 3144
}
In the future the "expressions attached to elements" will be extended
to also support user created non-stateful expressions to allow to
efficiently select beween a set of parameter sets, f.i. a set of log
statements with different prefixes based on the interface, which currently
require one rule each. This will most likely have to wait until the next
kernel version though.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Using a timer wheel for timewait sockets was nice ~15 years ago when
memory was expensive and machines had a single processor.
This does not scale, code is ugly and source of huge latencies
(Typically 30 ms have been seen, cpus spinning on death_lock spinlock.)
We can afford to use an extra 64 bytes per timewait sock and spread
timewait load to all cpus to have better behavior.
Tested:
On following test, /proc/sys/net/ipv4/tcp_tw_recycle is set to 1
on the target (lpaa24)
Before patch :
lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
419594
lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
437171
While test is running, we can observe 25 or even 33 ms latencies.
lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 20601ms
rtt min/avg/max/mdev = 0.020/0.217/25.771/1.535 ms, pipe 2
lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 20702ms
rtt min/avg/max/mdev = 0.019/0.183/33.761/1.441 ms, pipe 2
After patch :
About 90% increase of throughput :
lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
810442
lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
800992
And latencies are kept to minimal values during this load, even
if network utilization is 90% higher :
lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 19991ms
rtt min/avg/max/mdev = 0.023/0.064/0.360/0.042 ms
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The printed values are all of type unsigned integer, therefore use
%u instead of %d. Otherwise an user can face negative values.
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The printed values are all of type unsigned integer, therefore use
%u instead of %d. Otherwise an user can face negative values.
Fixes:
$ cat /proc/net/netfilter/nfnetlink_queue
0 29508 278 2 65531 0 2004213241 -2129885586 1
1 -27747 0 2 65531 0 0 0 1
2 -27748 0 2 65531 0 0 0 1
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The netlink portid is an unsigned integer, use this type
also in netfilter.
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There's an example net/netfilter/nft_expr_template.c example file in tree that
got out of sync along time, remove it.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Patrick McHardy <kaber@trash.net>
Support instantiating stateful expressions based on a template that
are associated with dynamically created set entries. The expressions
are evaluated when adding or updating the set element.
This allows to maintain per flow state using the existing set
infrastructure and expression types, with arbitrary definitions of
a flow.
Usage is currently restricted to anonymous sets, meaning only a single
binding can exist, since the desired semantics of multiple independant
bindings haven't been defined so far.
Examples (userspace syntax is still WIP):
1. Limit the rate of new SSH connections per host, similar to iptables
hashlimit:
flow ip saddr timeout 60s \
limit 10/second \
accept
2. Account network traffic between each set of /24 networks:
flow ip saddr & 255.255.255.0 . ip daddr & 255.255.255.0 \
counter
3. Account traffic to each host per user:
flow skuid . ip daddr \
counter
4. Account traffic for each combination of source address and TCP flags:
flow ip saddr . tcp flags \
counter
The resulting set content after a Xmas-scan look like this:
{
192.168.122.1 . fin | psh | urg : counter packets 1001 bytes 40040,
192.168.122.1 . ack : counter packets 74 bytes 3848,
192.168.122.1 . psh | ack : counter packets 35 bytes 3144
}
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a set flag to indicate that the set is used as a state table and
contains expressions for evaluation. This operation is mutually
exclusive with the mapping operation, so sets specifying both are
rejected. The lookup expression also rejects binding to state tables
since it only deals with loopup and map operations.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a flag to mark stateful expressions.
This is used for dynamic expression instanstiation to limit the usable
expressions. Strictly speaking only the dynset expression can not be
used in order to avoid recursion, but since dynamically instantiating
non-stateful expressions will simply create an identical copy, which
behaves no differently than the original, this limits to expressions
where it actually makes sense to dynamically instantiate them.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Preparation to attach expressions to set elements: add a set extension
type to hold an expression and dump the expression information with the
set element.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add helper functions for initializing, cloning, dumping and destroying
a single expression that is not part of a rule.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch changes sets to support variable sized set element keys / data
up to 64 bytes each by using variable sized set extensions. This allows
to use concatenations with bigger data items suchs as IPv6 addresses.
As a side effect, small keys/data now don't require the full 16 bytes
of struct nft_data anymore but just the space they need.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a size argument to nft_data_init() and pass in the available space.
This will be used by the following patches to support variable sized
set element data.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Switch the nf_tables registers from 128 bit addressing to 32 bit
addressing to support so called concatenations, where multiple values
can be concatenated over multiple registers for O(1) exact matches of
multiple dimensions using sets.
The old register values are mapped to areas of 128 bits for compatibility.
When dumping register numbers, values are expressed using the old values
if they refer to the beginning of a 128 bit area for compatibility.
To support concatenations, register loads of less than a full 32 bit
value need to be padded. This mainly affects the payload and exthdr
expressions, which both unconditionally zero the last word before
copying the data.
Userspace fully passes the testsuite using both old and new register
addressing.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add helper functions to parse and dump register values in netlink attributes.
These helpers will later be changed to take care of translation between the
old 128 bit and the new 32 bit register numbers.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Simple conversion to use u32 pointers to the beginning of the data
area to keep follow up patches smaller.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only needlessly complicates things due to requiring specific argument
types. Use memcmp directly.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Simple conversion to use u32 pointers to the beginning of the registers
to keep follow up patches smaller.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Replace the array of registers passed to expressions by a struct nft_regs,
containing the verdict as a seperate member, which aliases to the
NFT_REG_VERDICT register.
This is needed to seperate the verdict from the data registers completely,
so their size can be changed.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Change nft_validate_input_register() to not only validate the input
register number, but also the length of the load, and rename it to
nft_validate_register_load() to reflect that change.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
All users of nft_validate_register_store() first invoke
nft_validate_output_register(). There is in fact no use for using it
on its own, so simplify the code by folding the functionality into
nft_validate_register_store() and kill it.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In preparation of validating the length of a register store, use
nft_validate_register_store() in nft_lookup instead of open coding the
validation.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The existing name is ambiguous, data is loaded as well when we read from
a register. Rename to nft_validate_register_store() for clarity and
consistency with the upcoming patch to introduce its counterpart,
nft_validate_register_load().
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For values spanning multiple registers, we need to validate that enough
space is available from the destination register onwards. Add a len
argument to nft_validate_data_load() and consolidate the existing length
validations in preparation of that.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
David S. Miller
Eric Dumazet
Richard Weinberger
Pablo Neira Ayuso
Patrick McHardy