The current ebpf/Makefile.am have the problem that clang compile
errors still result in an ELF .bpf output file. This is obviously
problematic as the problem is first seen runtime when loading
the bpf-prog. This is caused by the uses of a pipe from
clang to llc.
To address this problem, split up the clang and llc invocations
up into two separate commands, to get proper reaction based on
the compiler exit code. The clang compiler is used as a
frontend (+ optimizer) and instructed (via -S -emit-llvm) to
generate LLVM IR (Intermediate Representation) with suffix .ll.
The LLVM llc command is used as a compiler backend taking IR and
producing BPF machine bytecode, and storing this into a ELF
object. In the last step the IR .ll suffix code it removed.
The official documentation of the IR language:
http://llvm.org/docs/LangRef.html
Also fix the previous make portability warning:
'%-style pattern rules are a GNU make extension'
I instead use some static pattern rules:
https://www.gnu.org/software/make/manual/html_node/Static-Usage.html
Signed-off-by: Jesper Dangaard Brouer <netoptimizer@brouer.com>
Enable compiling eBPF programs with clang -target bpf.
This is mostly to workaround a bug in libbpf, where clang > ver 4.0.0
generates some ELF sections (.eh_frame) when -target bpf is NOT specified,
and libbpf fails loading such files.
Notice libbpf is provided by the kernel, and in kernel v4.16 the library
will contain the needed function for attaching to the XDP hook.
Kernel commit 949abbe88436 ("libbpf: add function to setup XDP")
https://git.kernel.org/torvalds/c/949abbe88436
The library fix has reached kernel v4.16 but the workaround for Suricata
is interesting anyway in case people use a kernel v4.15.
Signed-off-by: Jesper Dangaard Brouer <netoptimizer@brouer.com>
This patch prepares code before enabling the clang -target bpf.
The clang compiler does not like #include <stdint.h> when
using '-target bpf' it will fail with:
fatal error: 'gnu/stubs-32.h' file not found
This is because using clang -target bpf, then clang will have '__bpf__'
defined instead of '__x86_64__' hence the gnu/stubs-32.h include
attempt as /usr/include/gnu/stubs.h contains, on x86_64:
#if !defined __x86_64__
# include <gnu/stubs-32.h>
#endif
#if defined __x86_64__ && defined __LP64__
# include <gnu/stubs-64.h>
#endif
#if defined __x86_64__ && defined __ILP32__
# include <gnu/stubs-x32.h>
#endif
This can be worked around by installing the 32-bit version of
glibc-devel.i686 on your distribution.
But the BPF programs does not really need to include stdint.h,
if converting:
uint64_t -> __u64
uint32_t -> __u32
uint16_t -> __u16
uint8_t -> __u8
This patch does this type syntax conversion.
The build of a ebpf files had an issue for system like Debian
because they don't have a asm/types.h in the include path if the
architecture is not defined which is the case due to target bpf.
This results in:
clang-5.0 -Wall -Iinclude -O2 \
-D__KERNEL__ -D__ASM_SYSREG_H \
-target bpf -S -emit-llvm vlan_filter.c -o vlan_filter.ll
In file included from vlan_filter.c:19:
In file included from include/linux/bpf.h:11:
/usr/include/linux/types.h:5:10: fatal error: 'asm/types.h' file not
found
#include <asm/types.h>
^~~~~~~~~~~~~
1 error generated.
Makefile:523: recipe for target 'vlan_filter.bpf' failed
This patch fixes the issue by adding a include path setting the
architecture to the one of the builder.
Signed-off-by: Jesper Dangaard Brouer <netoptimizer@brouer.com>
Sidned-off-by: Eric Leblond <eric@regit.org>
When the filedata logger is enabled (file extraction), but a file is not
stored due to no rules matching to force this, the file would never be
freed.
This was caused by a check in the file pruning logic that only freed a
file when the FILE_STORED flag was set. However files can also have the
FILE_NOSTORE flag set which indicates that a file won't be stored.
This patch makes sure that both conditions lead to file pruning.
Allows matching on stickybuffers. Like dsize, it allows matching on
exact values, greater than and less than, and ranges.
For streaming buffers, such as HTTP bodies, the final size of the
body is only known at the end of the transaction.
As we can have multiple files per TX we use the multi inspect
buffer support.
By using this API file_data supports transforms.
Redo part of the flash decompression as a hard coded built-in sort
of transform.
Make sure content is applied to the transformed version of a buffer.
Support content with its modifiers, and also isdataat, pcre, bytetest
and bytejump.
Move previously global table into detect engine ctx. Now that we
can register buffers at rule loading time we need to take concurrency
into account.
Move DetectBufferType to detect.h and update DetectBufferCtx API calls
to include a detect engine ctx reference.
Introduce InspectionBuffer a structure for passing data between
prefilters, transforms and inspection engines.
At rule parsing time, we'll register new unique 'DetectBufferType's
for a 'parent' buffer (e.g. pure file_data) with its transformations.
Each unique combination of buffer with transformations gets it's
own buffer id.
Similarly, mpm registration and inspect engine registration will be
copied from the 'parent' (again, e.g. pure file_data) to the new id's.
The transforms are called from within the prefilter engines themselves.
Provide generic MPM matching and setup callbacks. Can be used by
keywords to avoid needless code duplication. Supports transformations.
Use unique name for profiling, to distinguish between pure buffers
and buffers with transformation.
Add new registration calls for mpm/prefilters and inspect engines.
Inspect engine api v2: Pass engine to itself. Add generic engine that
uses GetData callback and other registered settings.
The generic engine should be usable for every 'simple' case where
there is just a single non-streaming buffer. For example HTTP uri.
The v2 API assumes that registered MPM implements transformations.
Add util func to set new transform in rule and add util funcs for rule
parsing.
Remove DetectAppLayerInspectEngineRegister for TOCLIENT direction
because Modbus inspection engine is only performing in request (TOSERVER).
Detect Value keyword in read access rule. In read access, match on value
is not possible.
Update Modbus keyword documentation.
When loading an empty file, libyaml will fire a single scalar
event causing us to create a key that contains an empty string.
We're not interested in this, so skip an empty scalar value
when expecting a key.
Redmine issue:
https://redmine.openinfosecfoundation.org/issues/2418
Also remove the now useless 'state' argument from the SetTxDetectState
calls. For those app-layer parsers that use a state == tx approach,
the state pointer is passed as tx.
Update app-layer parsers to remove the unused call and update the
modified call.
Until now, the transaction space is assumed to be terse. Transactions
are handled sequentially so the difference between the lowest and highest
active tx id's is small. For this reason the logic of walking every id
between the 'minimum' and max id made sense. The space might look like:
[..........TTTT]
Here the looping starts at the first T and loops 4 times.
This assumption isn't a great fit though. A protocol like NFS has 2 types
of transactions. Long running file transfer transactions and short lived
request/reply pairs are causing the id space to be sparse. This leads to
a lot of unnecessary looping in various parts of the engine, but most
prominently: detection, tx house keeping and tx logging.
[.T..T...TTTT.T]
Here the looping starts at the first T and loops for every spot, even
those where no tx exists anymore.
Cases have been observed where the lowest tx id was 2 and the highest
was 50k. This lead to a lot of unnecessary looping.
This patch add an alternative approach. It allows a protocol to register
an iterator function, that simply returns the next transaction until
all transactions are returned. To do this it uses a bit of state the
caller must keep.
The registration is optional. If no iterator is registered the old
behaviour will be used.
Eric Leblond
Jesper Dangaard Brouer
Victor Julien
Andreas Herz
Jason Ish
Philippe Antoine
David DIALLO
Pierre Chifflier