This renames Config to config.mk and includes more Make input.
Now configure generates all the required CFLAGS and LDLIBS for
the optional libraries.
Also, use pkg-config to test for libelf, rather than using a test
program. This makes it consistent with other libraries.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Commit 69fed534a5 ("change how Config is used in Makefile's") moved
HAVE_MNL specific CFLAGS/LDLIBS for building with libmnl out of the
top level Makefile into sub-Makefiles. However, it also removed the
HAVE_ELF specific CFLAGS/LDLIBS entirely, which breaks the BPF object
loader for tc and ip with "No ELF library support compiled in." despite
having libelf detected in configure script. Fix it similarly as in
69fed534a5 for HAVE_ELF.
Fixes: 69fed534a5 ("change how Config is used in Makefile's")
Reported-by: Jeffrey Panneman <jeffrey.panneman@tno.nl>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
For example, forward tcp traffic to veth0 and set
destination mac address to 11:22:33:44:55:66 :
$ tc filter add dev enp0s9 protocol ip parent ffff: \
flower \
ip_proto tcp \
action pedit ex munge \
eth dst set 11:22:33:44:55:66 \
action mirred egress \
redirect dev veth0
Signed-off-by: Amir Vadai <amir@vadai.me>
Rebuilding libnetlink doesn't trigger rebuild of tc, which is wrong
(especially so for builds where libnetlink.a gets statically linked into
tc). Fix that by introducing an explicit dependency.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The sample tc action allows sampling packets matching a classifier. It
peeks randomly packets, and samples them using the psample netlink
channel. The user can specify the psample group, which the packet will be
sampled to, the sampling rate and the packet truncation (to save
kernel-user traffic).
The sampled packets contain informative metadata, for example, the input
interface and the original packet length.
The action syntax:
tc filter add [...] \
action sample rate <RATE> group <GROUP> [trunc <SIZE>]
[...]
Where:
RATE := The sampling rate which is the ratio of packets observed at the
data source to the samples generated
GROUP := the psample module sampling group
SIZE := optional truncation size
An example for a common usecase of the sample tc action: to sample ingress
traffic from interface eth1, one may use the commands:
tc qdisc add dev eth1 handle ffff: ingress
tc filter add dev eth1 parent ffff: \
matchall action sample rate 12 group 4
Where the first command adds an ingress qdisc and the second starts
sampling randomly with an average of one sampled packet per 12 packets
on dev eth1 to psample group 4.
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
This action could be used before redirecting packets to a shared tunnel
device, or when redirecting packets arriving from a such a device.
The 'unset' action is optional. It is used to explicitly unset the
metadata created by the tunnel device during decap. If not used, the
metadata will be released automatically by the kernel.
The 'set' operation, will set the metadata with the specified values for
the encap.
For example, the following flower filter will forward all ICMP packets
destined to 11.11.11.2 through the shared vxlan device 'vxlan0'. Before
redirecting, a metadata for the vxlan tunnel is created using the
tunnel_key action and it's arguments:
$ tc filter add dev net0 protocol ip parent ffff: \
flower \
ip_proto 1 \
dst_ip 11.11.11.2 \
action tunnel_key set \
src_ip 11.11.0.1 \
dst_ip 11.11.0.2 \
id 11 \
action mirred egress redirect dev vxlan0
Signed-off-by: Amir Vadai <amir@vadai.me>
This work moves the bpf loader into the iproute2 library and reworks
the tc specific parts into generic code. It's useful as we can then
more easily support new program types by just having the same ELF
loader backend. Joint work with Thomas Graf. I hacked a rough start
of a test suite to make sure nothing breaks [1] and looks all good.
[1] https://github.com/borkmann/clsact/blob/master/test_bpf.sh
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Since 5cd1adba79 ("Update to current iptables headers") compilation
of iproute2 broke for systems without iptables-devel package [1].
Reason is that even though we fall back to build m_ipt.c, the include
depends on a xtables-version.h header, which only ships with
iptables-devel. Machines not having this package fail compilation with:
[...]
CC m_ipt.o
In file included from ../include/iptables.h:5:0,
from m_ipt.c:17:
../include/xtables.h:34:29: fatal error: xtables-version.h: No such file or directory
compilation terminated.
../Config:31: recipe for target 'm_ipt.o' failed
make[1]: *** [m_ipt.o] Error 1
The configure script only barks that package xtables was not found in
the pkg-config search path. The generated Config then only contains f.e.
TC_CONFIG_IPSET. In tc's Makefile we thus fall back to adding m_ipt.o
to TCMODULES. m_ipt.c then includes the local include/iptables.h header
copy, which includes the include/xtables.h copy. Latter then includes
xtables-version.h, which only ships with iptables-devel.
One way to resolve this is to skip this whole mess when pkg-config has
no xtables config available. I've carried something along these lines
locally for a while now, but it's just too annyoing. :/ Build works fine
now also when xtables.pc is not available.
[1] http://www.spinics.net/lists/netdev/msg366162.html
Fixes: 5cd1adba79 ("Update to current iptables headers")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The matchall classifier matches every packet and allows the user to apply
actions on it. In addition, it supports the skip_sw and skip_hw (as can
be found on u32 and flower filter) that direct the kernel to skip the
software/hardware processing of the actions.
This filter is very useful in usecases where every packet should be
matched. For example, packet mirroring (SPAN) can be setup very easily
using that filter.
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Similar to the Linux kernel and perf add infrastructure to reduce the
amount of output tossed to a user during a build. Full build output
can be obtained with 'make V=1'
Builds go from:
make[1]: Leaving directory `/home/dsa/iproute2.git/lib'
make[1]: Entering directory `/home/dsa/iproute2.git/ip'
gcc -Wall -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations -Wold-style-definition -Wformat=2 -O2 -I../include -DRESOLVE_HOSTNAMES -DLIBDIR=\"/usr/lib\" -DCONFDIR=\"/etc/iproute2\" -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -c -o ip.o ip.c
gcc -Wall -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations -Wold-style-definition -Wformat=2 -O2 -I../include -DRESOLVE_HOSTNAMES -DLIBDIR=\"/usr/lib\" -DCONFDIR=\"/etc/iproute2\" -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -c -o ipaddress.o ipaddress.c
to:
...
AR libutil.a
ip
CC ip.o
CC ipaddress.o
...
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
This action allows for a sending side to encapsulate arbitrary metadata
which is decapsulated by the receiving end.
The sender runs in encoding mode and the receiver in decode mode.
Both sender and receiver must specify the same ethertype.
At some point we hope to have a registered ethertype and we'll
then provide a default so the user doesnt have to specify it.
For now we enforce the user specify it.
Described in netdev01 paper:
"Distributing Linux Traffic Control Classifier-Action Subsystem"
Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
Also refer to IETF draft-ietf-forces-interfelfb-04.txt
Lets show example usage where we encode icmp from a sender towards
a receiver with an skbmark of 17; both sender and receiver use
ethertype of 0xdead to interop.
YYYY: Lets start with Receiver-side policy config:
xxx: add an ingress qdisc
sudo tc qdisc add dev $ETH ingress
xxx: any packets with ethertype 0xdead will be subjected to ife decoding
xxx: we then restart the classification so we can match on icmp at prio 3
sudo $TC filter add dev $ETH parent ffff: prio 2 protocol 0xdead \
u32 match u32 0 0 flowid 1:1 \
action ife decode reclassify
xxx: on restarting the classification from above if it was an icmp
xxx: packet, then match it here and continue to the next rule at prio 4
xxx: which will match based on skb mark of 17
sudo tc filter add dev $ETH parent ffff: prio 3 protocol ip \
u32 match ip protocol 1 0xff flowid 1:1 \
action continue
xxx: match on skbmark of 0x11 (decimal 17) and accept
sudo tc filter add dev $ETH parent ffff: prio 4 protocol ip \
handle 0x11 fw flowid 1:1 \
action ok
xxx: Lets show the decoding policy
sudo tc -s filter ls dev $ETH parent ffff: protocol 0xdead
xxx:
filter pref 2 u32
filter pref 2 u32 fh 800: ht divisor 1
filter pref 2 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 (rule hit 0 success 0)
match 00000000/00000000 at 0 (success 0 )
action order 1: ife decode action reclassify type 0x0
allow mark allow prio
index 11 ref 1 bind 1 installed 45 sec used 45 sec
Action statistics:
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
xxx:
Observe that above lists all metadatum it can decode. Typically these
submodules will already be compiled into a monolithic kernel or
loaded as modules
YYYY: Lets show the sender side now ..
xxx: Add an egress qdisc on the sender netdev
sudo tc qdisc add dev $ETH root handle 1: prio
xxx:
xxx: Match all icmp packets to 192.168.122.237/24, then
xxx: tag the packet with skb mark of decimal 17, then
xxx: Encode it with:
xxx: ethertype 0xdead
xxx: add skb->mark to whitelist of metadatum to send
xxx: rewrite target dst MAC address to 02:15:15:15:15:15
xxx:
sudo $TC filter add dev $ETH parent 1: protocol ip prio 10 u32 \
match ip dst 192.168.122.237/24 \
match ip protocol 1 0xff \
flowid 1:2 \
action skbedit mark 17 \
action ife encode \
type 0xDEAD \
allow mark \
dst 02:15:15:15:15:15
xxx: Lets show the encoding policy
filter pref 10 u32
filter pref 10 u32 fh 800: ht divisor 1
filter pref 10 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:2 (rule hit 118 success 0)
match c0a87a00/ffffff00 at 16 (success 0 )
match 00010000/00ff0000 at 8 (success 0 )
action order 1: skbedit mark 17
index 11 ref 1 bind 1 installed 3 sec used 3 sec
Action statistics:
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
action order 2: ife encode action pipe type 0xDEAD
allow mark dst 02:15:15:15:15:15
index 12 ref 1 bind 1 installed 3 sec used 3 sec
Action statistics:
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
xxx:
Now test by sending ping from sender to destination
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
This work follows upon commit 6256f8c9e4 ("tc, bpf: finalize eBPF
support for cls and act front-end") and takes up the idea proposed by
Hannes Frederic Sowa to spawn a shell (or any other command) that holds
generated eBPF map file descriptors.
File descriptors, based on their id, are being fetched from the same
unix domain socket as demonstrated in the bpf_agent, the shell spawned
via execvpe(2) and the map fds passed over the environment, and thus
are made available to applications in the fashion of std{in,out,err}
for read/write access, for example in case of iproute2's examples/bpf/:
# env | grep BPF
BPF_NUM_MAPS=3
BPF_MAP1=6 <- BPF_MAP_ID_QUEUE (id 1)
BPF_MAP0=5 <- BPF_MAP_ID_PROTO (id 0)
BPF_MAP2=7 <- BPF_MAP_ID_DROPS (id 2)
# ls -la /proc/self/fd
[...]
lrwx------. 1 root root 64 Apr 14 16:46 0 -> /dev/pts/4
lrwx------. 1 root root 64 Apr 14 16:46 1 -> /dev/pts/4
lrwx------. 1 root root 64 Apr 14 16:46 2 -> /dev/pts/4
[...]
lrwx------. 1 root root 64 Apr 14 16:46 5 -> anon_inode:bpf-map
lrwx------. 1 root root 64 Apr 14 16:46 6 -> anon_inode:bpf-map
lrwx------. 1 root root 64 Apr 14 16:46 7 -> anon_inode:bpf-map
The advantage (as opposed to the direct/native usage) is that now the
shell is map fd owner and applications can terminate and easily reattach
to descriptors w/o any kernel changes. Moreover, multiple applications
can easily read/write eBPF maps simultaneously.
To further allow users for experimenting with that, next step is to add
a small helper that can get along with simple data types, so that also
shell scripts can make use of bpf syscall, f.e to read/write into maps.
Generally, this allows for prepopulating maps, or any runtime altering
which could influence eBPF program behaviour (f.e. different run-time
classifications, skb modifications, ...), dumping of statistics, etc.
Reference: http://thread.gmane.org/gmane.linux.network/357471/focus=357860
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Add ability to add the netfilter connmark support.
Typical usage:
...lets tag outgoing icmp with mark 0x10..
iptables -tmangle -A PREROUTING -p icmp -j CONNMARK --set-mark 0x10
..add on ingress of $ETH an extractor for connmark...
tc filter add dev $ETH parent ffff: prio 4 protocol ip \
u32 match ip protocol 1 0xff \
flowid 1:1 \
action connmark continue
...if the connmark was 0x11, we police to a ridic rate of 10Kbps
tc filter add dev $ETH parent ffff: prio 5 protocol ip \
handle 0x11 fw flowid 1:1 \
action police rate 10kbit burst 10k
Other ways to use the connmark is to supply the zone, index and
branching choice. Refer to help.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
This work adds the tc frontend for kernel commit e2e9b6541dd4 ("cls_bpf:
add initial eBPF support for programmable classifiers").
A C-like classifier program (f.e. see e2e9b6541dd4) is being compiled via
LLVM's eBPF backend into an ELF file, that is then being passed to tc. tc
then loads, if any, eBPF maps and eBPF opcodes (with fixed-up eBPF map file
descriptors) out of its dedicated sections, and via bpf(2) into the kernel
and then the resulting fd via netlink down to cls_bpf. cls_bpf allows for
annotations, currently, I've used the file name for that, so that the user
can easily identify his filter when dumping configurations back.
Example usage:
clang -O2 -emit-llvm -c cls.c -o - | llc -march=bpf -filetype=obj -o cls.o
tc filter add dev em1 parent 1: bpf run object-file cls.o classid x:y
tc filter show dev em1 [...]
filter parent 1: protocol all pref 49152 bpf handle 0x1 flowid x:y cls.o
I placed the parser bits derived from Alexei's kernel sample, into tc_bpf.c
as my next step is to also add the same support for BPF action, so we can
have a fully fledged eBPF classifier and action in tc.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Proportional Integral controller Enhanced (PIE) is a scheduler to address the
bufferbloat problem.
We present here a lightweight design, PIE(Proportional Integral controller
Enhanced) that can effectively control the average queueing latency to a target
value. Simulation results, theoretical analysis and Linux testbed results have
shown that PIE can ensure low latency and achieve high link utilization under
various congestion situations. The design does not require per-packet
timestamp, so it incurs very small overhead and is simple enough to implement
in both hardware and software. "
For more information, please see technical paper about PIE in the IEEE
Conference on High Performance Switching and Routing 2013. A copy of the paper
can be found at ftp://ftpeng.cisco.com/pie/.
Please also refer to the IETF draft submission at
http://tools.ietf.org/html/draft-pan-tsvwg-pie-00
All relevant code, documents and test scripts and results can be found at
ftp://ftpeng.cisco.com/pie/.
For problems with the iproute2/tc or Linux kernel code, please contact Vijay
Subramanian (vijaynsu@cisco.com or subramanian.vijay@gmail.com) Mythili Prabhu
(mysuryan@cisco.com)
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: Mythili Prabhu <mysuryan@cisco.com>
CC: Dave Taht <dave.taht@bufferbloat.net>
This is the iproute2 part of the kernel patch "net: sched:
add BPF-based traffic classifier".
[Will re-submit later again for iproute2 when window for
-next submissions opens.]
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>
Simple action is already in the kernel for years now as an
example. This complements it with user space control.
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
On openSUSE 12.2 (at least) xtables.h is not installed in the system-wide
include dir but in /usr/include/iptables-1.4.16.3/. This results in the
following build failure:
em_ipset.c:26:21: fatal error: xtables.h: No such file or directory
Other includers of xtables.h already call out to pkg-config
Rather than hard coding `pkg-config`, use ${PKG_CONFIG} so people can
override it to their specific version (like when cross-compiling).
This is the same way the upstream pkg-config code works.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Hi,
When compiling iproute2-3.6.0 on a host that doesn't have iptables available, I get the following error:
gcc -Wall -Wstrict-prototypes -O2 -I../include -DRESOLVE_HOSTNAMES
-DLIBDIR=\"/usr/lib\" -DCONFDIR=\"/etc/iproute2\" -D_GNU_SOURCE
-DCONFIG_GACT -DCONFIG_GACT_PROB -DYY_NO_INPUT -c -o em_ipset.o
em_ipset.c
em_ipset.c:26:21: fatal error: xtables.h: No such file or directory
Fixed by the following patch, which guards the building of em_ipset.o on
the presence of suitable headers.
Thanks,
Matt.
This ematch enables effective filtering of CAN frames (AF_CAN) based
on CAN identifiers with masking of compared bits. Implementation
utilizes bitmap based classification for standard frame format (SFF)
which is optimized for minimal overhead.
Signed-off-by: Rostislav Lisovy <lisovy@gmail.com>
example usage:
tc filter add dev $dev parent $id: basic match not ipset'(foobar src)' ..
also updates iproute2/ematch_map, else tc complains:
Error: Unable to find ematch "ipset" in /etc/iproute2/ematch_map
Please assign a unique ID to the ematch kind the suggested entry is:
8 ipset
when trying to use this ematch.
(text ematch (5) only exists in kernel, a vlan ematch (6) exists neither in
kernel nor userspace, but kernel headers define TCF_EM_VLAN == 6).
Fair Queue Codel packet scheduler
Principles :
- Packets are classified (internal classifier or external) on flows.
- This is a Stochastic model (as we use a hash, several flows might
be hashed on same slot)
- Each flow has a CoDel managed queue.
- Flows are linked onto two (Round Robin) lists,
so that new flows have priority on old ones.
- For a given flow, packets are not reordered (CoDel uses a FIFO)
- head drops only.
- ECN capability is on by default.
- Very low memory footprint (64 bytes per flow)
tc qdisc ... fq_codel [ limit PACKETS ] [ flows number ]
[ target TIME ] [ interval TIME ] [ noecn ]
[ quantum BYTES ]
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dave Taht <dave.taht@bufferbloat.net>
Cc: Kathleen Nichols <nichols@pollere.com>
Cc: Van Jacobson <van@pollere.net>
Cc: Tom Herbert <therbert@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Nandita Dukkipati <nanditad@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Changli Gao <xiaosuo@gmail.com>
An implementation of CoDel AQM, from Kathleen Nichols and Van Jacobson.
http://queue.acm.org/detail.cfm?id=2209336
This AQM main input is no longer queue size in bytes or packets, but the
delay packets stay in (FIFO) queue.
As we don't have infinite memory, we still can drop packets in enqueue()
in case of massive load, but mean of CoDel is to drop packets in
dequeue(), using a control law based on two simple parameters :
target : target sojourn time (default 5ms)
interval : width of moving time window (default 100ms)
Selected packets are dropped, unless ECN is enabled and packets can get
ECN mark instead.
Usage: tc qdisc ... codel [ limit PACKETS ] [ target TIME ]
[ interval TIME ] [ ecn ]
qdisc codel 10: parent 1:1 limit 2000p target 3.0ms interval 60.0ms ecn
Sent 13347099587 bytes 8815805 pkt (dropped 0, overlimits 0 requeues 0)
rate 202365Kbit 16708pps backlog 113550b 75p requeues 0
count 116 lastcount 98 ldelay 4.3ms dropping drop_next 816us
maxpacket 1514 ecn_mark 84399 drop_overlimit 0
CoDel must be seen as a base module, and should be used keeping in mind
there is still a FIFO queue. So a typical setup will probably need a
hierarchy of several qdiscs and packet classifiers to be able to meet
whatever constraints a user might have.
One possible example would be to use fq_codel, which combines Fair
Queueing and CoDel, in replacement of sfq / sfq_red.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dave Taht <dave.taht@bufferbloat.net>
Define where is the are located the iproute2 config files.
Get rid of trailing slashes for paths in several file.
Signed-off-by: Christoph J. Thompson <cjsthompson@gmail.com>
LIBNETLINK will be defined in the main Makefile, so
both ../lib/libnetlink.a ../lib/libutil.a will be
automatically appended during linking. Otherwise
../lib/libnetlink.a ../lib/libutil.a will appear
twice during linking.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Building iproute2 in parallel might hit the race failure:
emp_ematch.l:2:30: fatal error: emp_ematch.yacc.h:
No such file or directory
make[1]: *** [emp_ematch.lex.o] Error 1
This is because we currently allow the yacc/lex files to generate and
compile in parallel. So add a simple dependency to make sure yacc has
finished before we attempt to compile the lex output.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Add the iproute2 support for the ACT_CSUM action. Can be used as
following, certainly in conjunction with the ACT_PEDIT action (pedit):
# In order to DNAT (stateless) IPv4 packet from 192.168.1.100 to
# 0x12345678 (18.52.86.120), and update the IPv4 header checksum and
# the UDP checksum (the last one, only if the packet is UDP).
tc filter add eth0 prio 1 protocol ip parent ffff: \
u32 match ip src 192.168.1.100/32 flowid :1 \
action pedit munge offset 16 u32 set 0x12345678 \
pipe csum ip and udp
# In order to alter destination address of IPv6 TCP packets from fc00::1
# and correct the TCP checksum (nothing happened? except maybe for
# checksums in the TCP payload ...).
tc filter add eth0 prio 1 protocol ipv6 parent ffff: \
u32 match ip6 src fc00::1/128 match ip6 protocol 0x06 0xff flowid :1 \
action pedit munge offset 24 u32 set 0x12345678 \
pipe csum tcp
The recent commit "iproute2: add option to build m_xt as a tc module"
(ab814d6355) looks like it wrongly included debug changes in the
install target. So drop the `echo` so the tc binary actually gets
installed again.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This will build the xt module (action ipt) of tc as a
shared object that is linked at runtime by tc if used,
rather then built into tc.
This is similar to how the atm qdisc support
is handled (q_atm.so).
Signed-off-by: Andreas Henriksson <andreas@xxxxxxxx>
Try to automatically detect iptables modules directory.
Make the configure script look for iptables modules.
This also makes it possible to specify it on the
command line while building via "make IPT_LIB_DIR=/foo/bar".
Signed-off-by: Andreas Henriksson <andreas@fatal.se>