This work finalizes both eBPF front-ends for the classifier and action
part in tc, it allows for custom ELF section selection, a simplified tc
command frontend (while keeping compat), reusing of common maps between
classifier and actions residing in the same object file, and exporting
of all map fds to an eBPF agent for handing off further control in user
space.
It also adds an extensive example of how eBPF can be used, and a minimal
self-contained example agent that dumps map data. The example is well
documented and hopefully provides a good starting point into programming
cls_bpf and act_bpf.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-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>
We need limits.h for LONG_MIN and LONG_MAX, sys/param.h for MIN and
sys/select for struct timeval.
This fixes the following compile errors with musl libc:
f_bpf.c: In function 'bpf_parse_opt':
f_bpf.c:181:12: error: 'LONG_MIN' undeclared (first use in this function)
if (h == LONG_MIN || h == LONG_MAX) {
^
...
tc_util.o: In function `print_tcstats2_attr':
tc_util.c:(.text+0x13fe): undefined reference to `MIN'
tc_util.c:(.text+0x1465): undefined reference to `MIN'
tc_util.c:(.text+0x14ce): undefined reference to `MIN'
tc_util.c:(.text+0x154c): undefined reference to `MIN'
tc_util.c:(.text+0x160a): undefined reference to `MIN'
tc_util.o:tc_util.c:(.text+0x174e): more undefined references to `MIN' follow
...
tc_stab.o: In function `print_size_table':
tc_stab.c:(.text+0x40f): undefined reference to `MIN'
...
fdb.c:247:30: error: 'ULONG_MAX' undeclared (first use in this function)
(vni >> 24) || vni == ULONG_MAX)
^
lnstat.h:28:17: error: field 'last_read' has incomplete type
struct timeval last_read; /* last time of read */
^
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
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>
Daniel Borkmann
Jiri Pirko
Jamal Hadi Salim
Natanael Copa
Daniel Borkmann