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>
eBPF has a data type which is a per CPU array. By adding one element
to the array it is in fact added to all per CPU arrays in the kernel.
This allows to have a lockless structure in the kernel even when doing
counter update.
In userspace, we need to update the flow bypass code to fetch all
elements of the per CPU arrays.
This patch implements bypass capability for af-packet.
The filter only bypass TCP and UDP in IPv4 and IPv6. It don't
don't bypass IPv6 with extended headers.
This patch also introduces a bypassed flow manager that takes
care of timeouting the bypassed flows. It uses a 60 sec
timeout on flow. As they are supposed to be active we can
try that. If they are not active then we don't care to get them
back in Suricata.
Jesper Dangaard Brouer
Eric Leblond