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>
The XDP CPU destination array/set, configured via xdp-cpu-redirect,
will always be fairly small. My different benchmarking showed that
the current modulo hashing into the CPU array can easily result in bad
distribution, expecially if the number of CPU is an even number.
This patch uses a proper hashing function on the input key. The key
used for hashing is inspired by the ippair hashing code in
src/tmqh-flow.c, and is based on the IP src + dst.
An important property is that the hashing is flow symmetric, meaning
that if the source and destintation gets swapped then the selected CPU
will remain the same. This is important for Suricate.
That hashing INITVAL (15485863 the 10^6th prime number) was fairly
arbitrary choosen, but experiments with kernel tree pktgen scripts
(pktgen_sample04_many_flows.sh +pktgen_sample05_flow_per_thread.sh)
showed this improved the distribution.
Signed-off-by: Jesper Dangaard Brouer <netoptimizer@brouer.com>
This patch adds a boolean option "xdp-cpu-redirect" to af-packet
interface configuration. If set, then the XDP filter will load
balance the skb creation on specified CPUs instead of doing the
creation on the CPU handling the packet. In the case of a card
with asymetric hashing this will allow to avoid saturating the
single CPU handling the trafic.
The XDP filter must contains a set of map allowing load balancing.
This is the case of xdp_filter.bpf.
Fixed-by: Jesper Dangaard Brouer <netoptimizer@brouer.com>
Eric Leblond
Jesper Dangaard Brouer