AF_PACKET is not setting the engine mode to IPS when some
interfaces are peered and use IPS mode. This is due to the
fact, it is possible to peer 2 interfaces and run an IPS on
them and have a third one that is running in normal IDS mode.
In fact this choice is the bad one as unwanted side effect is
that there is no drop log and that stream inline is not used.
To fix that, this patch puts suricata in IPS mode as soon as
there is two interfaces in IPS mode. And it displays a error
message to warn user that the accuracy of detection on IDS only
interfaces will be low.
A cast during the reading of a configuration variable was invalid
because a 16 bit integer was cast to a 32 bit integer. The called
function is only setting the pointer value to 1 or 0 so there is
no real issue there.
When handling error case on SCMallog, SCCalloc or SCStrdup
we are in an unlikely case. This patch adds the unlikely()
expression to indicate this to gcc.
This patch has been obtained via coccinelle. The transformation
is the following:
@istested@
identifier x;
statement S1;
identifier func =~ "(SCMalloc|SCStrdup|SCCalloc)";
@@
x = func(...)
... when != x
- if (x == NULL) S1
+ if (unlikely(x == NULL)) S1
Flush all waiting packets to be in sync with kernel when drop
occurs. This mode can be activated by setting use-emergency-flush
to yes in the interface configuration.
This patch adds a new feature to AF_PACKET capture mode. It is now
possible to use AF_PACKET in IPS and TAP mode: all traffic received
on a interface will be forwarded (at the Ethernet level) to an other
interface. To do so, Suricata create a raw socket and sends the receive
packets to a interface designed in the configuration file.
This patch adds two variables to the configuration of af-packet
interface:
copy-mode: ips or tap
copy-iface: eth1 #the interface where packet are copied
If copy-mode is set to ips then the packet wth action DROP are not
copied to the destination interface. If copy-mode is set to tap,
all packets are copied to the destination interface.
Any other value of copy-mode results in the feature to be unused.
There is no default interface for copy-iface and the variable has
to be set for the ids or tap mode to work.
For now, this feature depends of the release data system. This
implies you need to activate the ring mode and zero copy. Basically
use-mmap has to be set to yes.
This patch adds a peering of AF_PACKET sockets from the thread on
one interface to the threads on another interface. Peering is
necessary as if we use an other socket the capture socket receives
all emitted packets. This is made using a new AFPPeer structure to
avoid direct interaction between AFPTreadVars.
There is currently a bug in Linux kernel (prior to 3.6) and it is
not possible to use multiple threads.
You need to setup two interfaces with equality on the threads
variable. copy-mode variable must be set on the two interfaces
and use-mmap must be set to activated.
A valid configuration for an IPS using eth0 and vboxnet1 interfaces
will look like:
af-packet:
- interface: eth0
threads: 1
defrag: yes
cluster-type: cluster_flow
cluster-id: 98
copy-mode: ips
copy-iface: vboxnet1
buffer-size: 64535
use-mmap: yes
- interface: vboxnet1
threads: 1
cluster-id: 97
defrag: yes
cluster-type: cluster_flow
copy-mode: ips
copy-iface: eth0
buffer-size: 64535
use-mmap: yes
The mmaped mode was using a too small ring buffer size which was
not able to handle burst of packets coming from the network. This
may explain the important packet loss rate observed by Edward
Fjellskål.
This patch increases the default value and adds a ring-size
variable which can be used to manually tune the value.
clang was issuing some warnings related to unused return in function.
This patch adds some needed error treatment and ignore the rest of the
warnings by adding a cast to void.
This patch adds support for BPF in AF_PACKET running
mode. The command line syntax is the same as the one
used of PF_RING.
The method is the same too: The pcap_compile__nopcap()
function is used to build the BPF filter. It is then
injected into the kernel with a setsockopt() call. If
the adding of the BPF fail, suricata exit.
This patch adds mmap support for af-packet. Suricata now makes
use of the ring buffer feature of AF_PACKET if 'use-mmap' variable
is set to yes on an interface.
This flag adds variable to disable offloading detection. The effect
of the flag is to avoid to transmit auxiliary data at each packet.
This could result in a potential performance gain.
This patch modifies the RunModeSetLiveCaptureAuto() prototype to
be able to detect that a 'threads' variable (telling how much
threads must listen to one socket in IDS mode) has been used
in the configuration file. It then print a warning message
if this is the case.
Previous commits have considerabily empowered the "single" mode which
could contain multiple threads. This behaviour was not a target for
this runmode and the following patch remedies to the situation by
introducing the "workers" mode where each thread do all the tasks
from acquisition to logging. This runmode is currently implemented
for af-packet and pf-ring.
A devide configuration can be used by multiple threads. It is thus
necessary to wait that all threads stop using the configuration before
freeing it. This patch introduces an atomic counter and a free function
which has to be called by each thread when it will not use anymore
the structure. If the configuration is not used anymore, it is freed
by the free function.
This patch adds multi interface support to AF_PACKET. A structure
is used at thread creation to give all needed information to the
input module. Parsing of the options is done in runmode preparation
through a dedicated function which return the configuration in a
structure usable by thread creation.
This patch handles the end of AF_PACKET socket support work. It
provides conditional compilation, autofp and single runmode.
It also adds a 'defrag' option which is used to activate defrag
support in kernel to avoid rx_hash computation in flow mode to fail
due to fragmentation.
This patch contains some fixes by Anoop Saldanha, and incorporate
change following review by Anoop Saldanha and Victor Julien.
AF_PACKET support is only build if the --enable-af-packet flag is
given to the configure command line. Detection of code availability
is also done: a check of the existence of AF_PACKET in standard
header is done. It seems this variable is Linux specific and it
should be enough to avoid compilation of AF_PACKET support on other
OSes.
Compilation does not depend on up-to-date headers on the system. If
none are present, wemake our own declaration of FANOUT variables. This
will permit compilation of the feature for system where only the kernel
has been updated to a version superior to 3.1.
Eric Leblond
Anoop Saldanha
pi-rho
Victor Julien
Anoop Saldanha