[iproute2-next,0/5] iproute2: add libbpf support

Message ID	20201023033855.3894509-1-haliu@redhat.com (mailing list archive)
Headers	show Return-Path: <SRS0=aZOz=D6=vger.kernel.org=bpf-owner@kernel.org> From: Hangbin Liu <haliu@redhat.com> To: Stephen Hemminger <stephen@networkplumber.org>, Daniel Borkmann <daniel@iogearbox.net>, David Ahern <dsahern@gmail.com>, Alexei Starovoitov <ast@kernel.org> Cc: Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>, David Miller <davem@davemloft.net>, Jesper Dangaard Brouer <brouer@redhat.com>, netdev@vger.kernel.org, bpf@vger.kernel.org, Jiri Benc <jbenc@redhat.com>, Andrii Nakryiko <andrii@kernel.org>, =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rge?= =?utf-8?q?nsen?= <toke@redhat.com>, Hangbin Liu <haliu@redhat.com> Subject: [PATCH iproute2-next 0/5] iproute2: add libbpf support Date: Fri, 23 Oct 2020 11:38:50 +0800 Message-Id: <20201023033855.3894509-1-haliu@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	iproute2: add libbpf support \| expand [iproute2-next,0/5] iproute2: add libbpf support [iproute2-next,1/5] configure: add check_libbpf() for later libbpf support [iproute2-next,2/5] lib: rename bpf.c to bpf_legacy.c [iproute2-next,3/5] lib: add libbpf support [iproute2-next,4/5] examples/bpf: move struct bpf_elf_map defined maps to legacy folder [iproute2-next,5/5] examples/bpf: add bpf examples with BTF defined maps

Hangbin Liu Oct. 23, 2020, 3:38 a.m. UTC

This series converts iproute2 to use libbpf for loading and attaching
BPF programs when it is available. This means that iproute2 will
correctly process BTF information and support the new-style BTF-defined
maps, while keeping compatibility with the old internal map definition
syntax.

This is achieved by checking for libbpf at './configure' time, and using
it if available. By default the system libbpf will be used, but static
linking against a custom libbpf version can be achieved by passing
LIBBPF_DIR to configure. FORCE_LIBBPF can be set to force configure to
abort if no suitable libbpf is found (useful for automatic packaging
that wants to enforce the dependency).

The old iproute2 bpf code is kept and will be used if no suitable libbpf
is available. When using libbpf, wrapper code ensures that iproute2 will
still understand the old map definition format, including populating
map-in-map and tail call maps before load.

The examples in bpf/examples are kept, and a separate set of examples
are added with BTF-based map definitions for those examples where this
is possible (libbpf doesn't currently support declaratively populating
tail call maps).

At last, Thanks a lot for Toke's help on this patch set.

Here are the test results with patched iproute2:

== setup env
# clang -O2 -Wall -g -target bpf -c bpf_graft.c -o btf_graft.o
# clang -O2 -Wall -g -target bpf -c bpf_map_in_map.c -o btf_map_in_map.o
# clang -O2 -Wall -g -target bpf -c bpf_shared.c -o btf_shared.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_cyclic.c -o bpf_cyclic.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_graft.c -o bpf_graft.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_map_in_map.c -o bpf_map_in_map.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_shared.c -o bpf_shared.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_tailcall.c -o bpf_tailcall.o
# rm -rf /sys/fs/bpf/xdp/globals
# /root/iproute2/ip/ip link add type veth
# /root/iproute2/ip/ip link set veth0 up
# /root/iproute2/ip/ip link set veth1 up


== Load objs
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_graft.o sec aaa
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 4 tag 3056d2382e53f27c jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
4: xdp  name cls_aaa  tag 3056d2382e53f27c  gpl
        loaded_at 2020-10-22T08:04:21-0400  uid 0
        xlated 80B  jited 71B  memlock 4096B
        btf_id 5
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_map_in_map.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 8 tag 4420e72b2a601ed7 jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc  map_inner  map_outer
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
8: xdp  name imain  tag 4420e72b2a601ed7  gpl
        loaded_at 2020-10-22T08:04:23-0400  uid 0
        xlated 336B  jited 193B  memlock 4096B  map_ids 3
        btf_id 10
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_shared.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 12 tag 9cbab549c3af3eab jited
# ls /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef:
map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc  map_inner  map_outer
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
4: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
12: xdp  name imain  tag 9cbab549c3af3eab  gpl
        loaded_at 2020-10-22T08:04:25-0400  uid 0
        xlated 224B  jited 139B  memlock 4096B  map_ids 4
        btf_id 15
# /root/iproute2/ip/ip link set veth0 xdp off


== Load objs again to make sure maps could be reused
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_graft.o sec aaa
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 16 tag 3056d2382e53f27c jited
# ls /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef:
map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc  map_inner  map_outer
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
4: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
16: xdp  name cls_aaa  tag 3056d2382e53f27c  gpl
        loaded_at 2020-10-22T08:04:27-0400  uid 0
        xlated 80B  jited 71B  memlock 4096B
        btf_id 20
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_map_in_map.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 20 tag 4420e72b2a601ed7 jited
# ls /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef:
map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc  map_inner  map_outer
# bpftool map show                                                                                                                                                                   [236/4518]
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
4: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
20: xdp  name imain  tag 4420e72b2a601ed7  gpl
        loaded_at 2020-10-22T08:04:29-0400  uid 0
        xlated 336B  jited 193B  memlock 4096B  map_ids 3
        btf_id 25
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_shared.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 24 tag 9cbab549c3af3eab jited
# ls /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef:
map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc  map_inner  map_outer
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
4: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
24: xdp  name imain  tag 9cbab549c3af3eab  gpl
        loaded_at 2020-10-22T08:04:31-0400  uid 0
        xlated 224B  jited 139B  memlock 4096B  map_ids 4
        btf_id 30
# /root/iproute2/ip/ip link set veth0 xdp off
# rm -rf /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals

== Testing if we can load new-style objects (using xdp-filter as an example)
# /root/iproute2/ip/ip link set veth0 xdp obj /usr/lib64/bpf/xdpfilt_alw_all.o sec xdp_filter
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 28 tag e29eeda1489a6520 jited
# ls /sys/fs/bpf/xdp/globals
filter_ethernet  filter_ipv4  filter_ipv6  filter_ports  xdp_stats_map
# bpftool map show
5: percpu_array  name xdp_stats_map  flags 0x0
        key 4B  value 16B  max_entries 5  memlock 4096B
        btf_id 35
6: percpu_array  name filter_ports  flags 0x0
        key 4B  value 8B  max_entries 65536  memlock 1576960B
        btf_id 35
7: percpu_hash  name filter_ipv4  flags 0x0
        key 4B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
8: percpu_hash  name filter_ipv6  flags 0x0
        key 16B  value 8B  max_entries 10000  memlock 1142784B
        btf_id 35
9: percpu_hash  name filter_ethernet  flags 0x0
        key 6B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
# bpftool prog show
28: xdp  name xdpfilt_alw_all  tag e29eeda1489a6520  gpl
        loaded_at 2020-10-22T08:04:33-0400  uid 0
        xlated 2408B  jited 1405B  memlock 4096B  map_ids 9,5,7,8,6
        btf_id 35
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj /usr/lib64/bpf/xdpfilt_alw_ip.o sec xdp_filter
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 32 tag 2f2b9dbfb786a5a2 jited
# ls /sys/fs/bpf/xdp/globals
filter_ethernet  filter_ipv4  filter_ipv6  filter_ports  xdp_stats_map
# bpftool map show
5: percpu_array  name xdp_stats_map  flags 0x0
        key 4B  value 16B  max_entries 5  memlock 4096B
        btf_id 35
6: percpu_array  name filter_ports  flags 0x0
        key 4B  value 8B  max_entries 65536  memlock 1576960B
        btf_id 35
7: percpu_hash  name filter_ipv4  flags 0x0
        key 4B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
8: percpu_hash  name filter_ipv6  flags 0x0
        key 16B  value 8B  max_entries 10000  memlock 1142784B
        btf_id 35
9: percpu_hash  name filter_ethernet  flags 0x0
        key 6B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
# bpftool prog show
32: xdp  name xdpfilt_alw_ip  tag 2f2b9dbfb786a5a2  gpl
        loaded_at 2020-10-22T08:04:35-0400  uid 0
        xlated 1336B  jited 778B  memlock 4096B  map_ids 7,8,5
        btf_id 40
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj /usr/lib64/bpf/xdpfilt_alw_tcp.o sec xdp_filter
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 36 tag 18c1bb25084030bc jited
# ls /sys/fs/bpf/xdp/globals
filter_ethernet  filter_ipv4  filter_ipv6  filter_ports  xdp_stats_map
# bpftool map show
5: percpu_array  name xdp_stats_map  flags 0x0
        key 4B  value 16B  max_entries 5  memlock 4096B
        btf_id 35
6: percpu_array  name filter_ports  flags 0x0
        key 4B  value 8B  max_entries 65536  memlock 1576960B
        btf_id 35
7: percpu_hash  name filter_ipv4  flags 0x0
        key 4B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
8: percpu_hash  name filter_ipv6  flags 0x0
        key 16B  value 8B  max_entries 10000  memlock 1142784B
        btf_id 35
9: percpu_hash  name filter_ethernet  flags 0x0
        key 6B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
# bpftool prog show
36: xdp  name xdpfilt_alw_tcp  tag 18c1bb25084030bc  gpl
        loaded_at 2020-10-22T08:04:37-0400  uid 0
        xlated 1128B  jited 690B  memlock 4096B  map_ids 6,5
        btf_id 45
# /root/iproute2/ip/ip link set veth0 xdp off
# rm -rf /sys/fs/bpf/xdp/globals


== Load new btf defined maps
# /root/iproute2/ip/ip link set veth0 xdp obj btf_graft.o sec aaa
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 40 tag 3056d2382e53f27c jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc
# bpftool map show
10: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
40: xdp  name cls_aaa  tag 3056d2382e53f27c  gpl
        loaded_at 2020-10-22T08:04:39-0400  uid 0
        xlated 80B  jited 71B  memlock 4096B
        btf_id 50
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj btf_map_in_map.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 44 tag 4420e72b2a601ed7 jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc  map_outer
# bpftool map show
10: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
11: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
13: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
44: xdp  name imain  tag 4420e72b2a601ed7  gpl
        loaded_at 2020-10-22T08:04:41-0400  uid 0
        xlated 336B  jited 193B  memlock 4096B  map_ids 13
        btf_id 55
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj btf_shared.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 48 tag 9cbab549c3af3eab jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc  map_outer  map_sh
# bpftool map show
10: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
11: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
13: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
14: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
48: xdp  name imain  tag 9cbab549c3af3eab  gpl
        loaded_at 2020-10-22T08:04:43-0400  uid 0
        xlated 224B  jited 139B  memlock 4096B  map_ids 14
        btf_id 60
# /root/iproute2/ip/ip link set veth0 xdp off
# rm -rf /sys/fs/bpf/xdp/globals


== Test load objs by tc
# /root/iproute2/tc/tc qdisc add dev veth0 ingress
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_cyclic.o sec 0xabccba/0
# /root/iproute2/tc/tc filter add dev veth0 parent ffff: bpf obj bpf_graft.o
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_tailcall.o sec 42/0
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_tailcall.o sec 42/1
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_tailcall.o sec 43/0
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_tailcall.o sec classifier
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
# ls /sys/fs/bpf/xdp/37e88cb3b9646b2ea5f99ab31069ad88db06e73d /sys/fs/bpf/xdp/fc68fe3e96378a0cba284ea6acbe17e898d8b11f /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/37e88cb3b9646b2ea5f99ab31069ad88db06e73d:
jmp_tc

/sys/fs/bpf/xdp/fc68fe3e96378a0cba284ea6acbe17e898d8b11f:
jmp_ex  jmp_tc  map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc
# bpftool map show
15: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
        owner_prog_type sched_cls  owner jited
16: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
        owner_prog_type sched_cls  owner jited
17: prog_array  name jmp_ex  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
        owner_prog_type sched_cls  owner jited
18: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 2  memlock 4096B
        owner_prog_type sched_cls  owner jited
19: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
52: sched_cls  name cls_loop  tag 3e98a40b04099d36  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 168B  jited 133B  memlock 4096B  map_ids 15
        btf_id 65
56: sched_cls  name cls_entry  tag 0fbb4d9310a6ee26  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 144B  jited 121B  memlock 4096B  map_ids 16
        btf_id 70
60: sched_cls  name cls_case1  tag e06a3bd62293d65d  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 328B  jited 216B  memlock 4096B  map_ids 19,17
        btf_id 75
66: sched_cls  name cls_case1  tag e06a3bd62293d65d  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 328B  jited 216B  memlock 4096B  map_ids 19,17
        btf_id 80
72: sched_cls  name cls_case1  tag e06a3bd62293d65d  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 328B  jited 216B  memlock 4096B  map_ids 19,17
        btf_id 85
78: sched_cls  name cls_case1  tag e06a3bd62293d65d  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 328B  jited 216B  memlock 4096B  map_ids 19,17
        btf_id 90
79: sched_cls  name cls_case2  tag ee218ff893dca823  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 336B  jited 218B  memlock 4096B  map_ids 19,18
        btf_id 90
80: sched_cls  name cls_exit  tag e78a58140deed387  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 288B  jited 177B  memlock 4096B  map_ids 19
        btf_id 90

I also run the following upstream kselftest with patches iproute2 and
all passed.

test_lwt_ip_encap.sh
test_xdp_redirect.sh
test_tc_redirect.sh
test_xdp_meta.sh
test_xdp_veth.sh
test_xdp_vlan.sh


Hangbin Liu (5):
  configure: add check_libbpf() for later libbpf support
  lib: rename bpf.c to bpf_legacy.c
  lib: add libbpf support
  examples/bpf: move struct bpf_elf_map defined maps to legacy folder
  examples/bpf: add bpf examples with BTF defined maps

 configure                                |  48 ++++
 examples/bpf/README                      |  18 +-
 examples/bpf/bpf_graft.c                 |  14 +-
 examples/bpf/bpf_map_in_map.c            |  37 ++-
 examples/bpf/bpf_shared.c                |  14 +-
 examples/bpf/{ => legacy}/bpf_cyclic.c   |   2 +-
 examples/bpf/legacy/bpf_graft.c          |  66 +++++
 examples/bpf/legacy/bpf_map_in_map.c     |  56 ++++
 examples/bpf/legacy/bpf_shared.c         |  53 ++++
 examples/bpf/{ => legacy}/bpf_tailcall.c |   2 +-
 include/bpf_api.h                        |  13 +
 include/bpf_util.h                       |  17 +-
 ip/ipvrf.c                               |   4 +-
 lib/Makefile                             |   6 +-
 lib/{bpf.c => bpf_legacy.c}              | 184 +++++++++++-
 lib/bpf_libbpf.c                         | 338 +++++++++++++++++++++++
 16 files changed, 824 insertions(+), 48 deletions(-)
 rename examples/bpf/{ => legacy}/bpf_cyclic.c (95%)
 create mode 100644 examples/bpf/legacy/bpf_graft.c
 create mode 100644 examples/bpf/legacy/bpf_map_in_map.c
 create mode 100644 examples/bpf/legacy/bpf_shared.c
 rename examples/bpf/{ => legacy}/bpf_tailcall.c (98%)
 rename lib/{bpf.c => bpf_legacy.c} (94%)
 create mode 100644 lib/bpf_libbpf.c

Hangbin Liu Oct. 28, 2020, 1:25 p.m. UTC | #1

This series converts iproute2 to use libbpf for loading and attaching
BPF programs when it is available. This means that iproute2 will
correctly process BTF information and support the new-style BTF-defined
maps, while keeping compatibility with the old internal map definition
syntax.

This is achieved by checking for libbpf at './configure' time, and using
it if available. By default the system libbpf will be used, but static
linking against a custom libbpf version can be achieved by passing
LIBBPF_DIR to configure. FORCE_LIBBPF can be set to force configure to
abort if no suitable libbpf is found (useful for automatic packaging
that wants to enforce the dependency).

The old iproute2 bpf code is kept and will be used if no suitable libbpf
is available. When using libbpf, wrapper code ensures that iproute2 will
still understand the old map definition format, including populating
map-in-map and tail call maps before load.

The examples in bpf/examples are kept, and a separate set of examples
are added with BTF-based map definitions for those examples where this
is possible (libbpf doesn't currently support declaratively populating
tail call maps).

At last, Thanks a lot for Toke's help on this patch set.


v2:
a) Remove self defined IS_ERR_OR_NULL and use libbpf_get_error() instead.
b) Add ipvrf with libbpf support.


Here are the test results with patched iproute2:

== setup env
# clang -O2 -Wall -g -target bpf -c bpf_graft.c -o btf_graft.o
# clang -O2 -Wall -g -target bpf -c bpf_map_in_map.c -o btf_map_in_map.o
# clang -O2 -Wall -g -target bpf -c bpf_shared.c -o btf_shared.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_cyclic.c -o bpf_cyclic.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_graft.c -o bpf_graft.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_map_in_map.c -o bpf_map_in_map.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_shared.c -o bpf_shared.o
# clang -O2 -Wall -g -target bpf -c legacy/bpf_tailcall.c -o bpf_tailcall.o
# rm -rf /sys/fs/bpf/xdp/globals
# /root/iproute2/ip/ip link add type veth
# /root/iproute2/ip/ip link set veth0 up
# /root/iproute2/ip/ip link set veth1 up


== Load objs
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_graft.o sec aaa
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 4 tag 3056d2382e53f27c jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
4: xdp  name cls_aaa  tag 3056d2382e53f27c  gpl
        loaded_at 2020-10-22T08:04:21-0400  uid 0
        xlated 80B  jited 71B  memlock 4096B
        btf_id 5
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_map_in_map.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 8 tag 4420e72b2a601ed7 jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc  map_inner  map_outer
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
8: xdp  name imain  tag 4420e72b2a601ed7  gpl
        loaded_at 2020-10-22T08:04:23-0400  uid 0
        xlated 336B  jited 193B  memlock 4096B  map_ids 3
        btf_id 10
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_shared.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 12 tag 9cbab549c3af3eab jited
# ls /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef:
map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc  map_inner  map_outer
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
4: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
12: xdp  name imain  tag 9cbab549c3af3eab  gpl
        loaded_at 2020-10-22T08:04:25-0400  uid 0
        xlated 224B  jited 139B  memlock 4096B  map_ids 4
        btf_id 15
# /root/iproute2/ip/ip link set veth0 xdp off


== Load objs again to make sure maps could be reused
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_graft.o sec aaa
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 16 tag 3056d2382e53f27c jited
# ls /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef:
map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc  map_inner  map_outer
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
4: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
16: xdp  name cls_aaa  tag 3056d2382e53f27c  gpl
        loaded_at 2020-10-22T08:04:27-0400  uid 0
        xlated 80B  jited 71B  memlock 4096B
        btf_id 20
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_map_in_map.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 20 tag 4420e72b2a601ed7 jited
# ls /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef:
map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc  map_inner  map_outer
# bpftool map show                                                                                                                                                                   [236/4518]
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
4: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
20: xdp  name imain  tag 4420e72b2a601ed7  gpl
        loaded_at 2020-10-22T08:04:29-0400  uid 0
        xlated 336B  jited 193B  memlock 4096B  map_ids 3
        btf_id 25
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj bpf_shared.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 24 tag 9cbab549c3af3eab jited
# ls /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef:
map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc  map_inner  map_outer
# bpftool map show
1: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
2: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
3: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
4: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
24: xdp  name imain  tag 9cbab549c3af3eab  gpl
        loaded_at 2020-10-22T08:04:31-0400  uid 0
        xlated 224B  jited 139B  memlock 4096B  map_ids 4
        btf_id 30
# /root/iproute2/ip/ip link set veth0 xdp off
# rm -rf /sys/fs/bpf/xdp/7a1422e90cd81478f97bc33fbd7782bcb3b868ef /sys/fs/bpf/xdp/globals

== Testing if we can load new-style objects (using xdp-filter as an example)
# /root/iproute2/ip/ip link set veth0 xdp obj /usr/lib64/bpf/xdpfilt_alw_all.o sec xdp_filter
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 28 tag e29eeda1489a6520 jited
# ls /sys/fs/bpf/xdp/globals
filter_ethernet  filter_ipv4  filter_ipv6  filter_ports  xdp_stats_map
# bpftool map show
5: percpu_array  name xdp_stats_map  flags 0x0
        key 4B  value 16B  max_entries 5  memlock 4096B
        btf_id 35
6: percpu_array  name filter_ports  flags 0x0
        key 4B  value 8B  max_entries 65536  memlock 1576960B
        btf_id 35
7: percpu_hash  name filter_ipv4  flags 0x0
        key 4B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
8: percpu_hash  name filter_ipv6  flags 0x0
        key 16B  value 8B  max_entries 10000  memlock 1142784B
        btf_id 35
9: percpu_hash  name filter_ethernet  flags 0x0
        key 6B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
# bpftool prog show
28: xdp  name xdpfilt_alw_all  tag e29eeda1489a6520  gpl
        loaded_at 2020-10-22T08:04:33-0400  uid 0
        xlated 2408B  jited 1405B  memlock 4096B  map_ids 9,5,7,8,6
        btf_id 35
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj /usr/lib64/bpf/xdpfilt_alw_ip.o sec xdp_filter
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 32 tag 2f2b9dbfb786a5a2 jited
# ls /sys/fs/bpf/xdp/globals
filter_ethernet  filter_ipv4  filter_ipv6  filter_ports  xdp_stats_map
# bpftool map show
5: percpu_array  name xdp_stats_map  flags 0x0
        key 4B  value 16B  max_entries 5  memlock 4096B
        btf_id 35
6: percpu_array  name filter_ports  flags 0x0
        key 4B  value 8B  max_entries 65536  memlock 1576960B
        btf_id 35
7: percpu_hash  name filter_ipv4  flags 0x0
        key 4B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
8: percpu_hash  name filter_ipv6  flags 0x0
        key 16B  value 8B  max_entries 10000  memlock 1142784B
        btf_id 35
9: percpu_hash  name filter_ethernet  flags 0x0
        key 6B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
# bpftool prog show
32: xdp  name xdpfilt_alw_ip  tag 2f2b9dbfb786a5a2  gpl
        loaded_at 2020-10-22T08:04:35-0400  uid 0
        xlated 1336B  jited 778B  memlock 4096B  map_ids 7,8,5
        btf_id 40
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj /usr/lib64/bpf/xdpfilt_alw_tcp.o sec xdp_filter
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 36 tag 18c1bb25084030bc jited
# ls /sys/fs/bpf/xdp/globals
filter_ethernet  filter_ipv4  filter_ipv6  filter_ports  xdp_stats_map
# bpftool map show
5: percpu_array  name xdp_stats_map  flags 0x0
        key 4B  value 16B  max_entries 5  memlock 4096B
        btf_id 35
6: percpu_array  name filter_ports  flags 0x0
        key 4B  value 8B  max_entries 65536  memlock 1576960B
        btf_id 35
7: percpu_hash  name filter_ipv4  flags 0x0
        key 4B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
8: percpu_hash  name filter_ipv6  flags 0x0
        key 16B  value 8B  max_entries 10000  memlock 1142784B
        btf_id 35
9: percpu_hash  name filter_ethernet  flags 0x0
        key 6B  value 8B  max_entries 10000  memlock 1064960B
        btf_id 35
# bpftool prog show
36: xdp  name xdpfilt_alw_tcp  tag 18c1bb25084030bc  gpl
        loaded_at 2020-10-22T08:04:37-0400  uid 0
        xlated 1128B  jited 690B  memlock 4096B  map_ids 6,5
        btf_id 45
# /root/iproute2/ip/ip link set veth0 xdp off
# rm -rf /sys/fs/bpf/xdp/globals


== Load new btf defined maps
# /root/iproute2/ip/ip link set veth0 xdp obj btf_graft.o sec aaa
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 40 tag 3056d2382e53f27c jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc
# bpftool map show
10: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
40: xdp  name cls_aaa  tag 3056d2382e53f27c  gpl
        loaded_at 2020-10-22T08:04:39-0400  uid 0
        xlated 80B  jited 71B  memlock 4096B
        btf_id 50
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj btf_map_in_map.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 44 tag 4420e72b2a601ed7 jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc  map_outer
# bpftool map show
10: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
11: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
13: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
44: xdp  name imain  tag 4420e72b2a601ed7  gpl
        loaded_at 2020-10-22T08:04:41-0400  uid 0
        xlated 336B  jited 193B  memlock 4096B  map_ids 13
        btf_id 55
# /root/iproute2/ip/ip link set veth0 xdp off
# /root/iproute2/ip/ip link set veth0 xdp obj btf_shared.o sec ingress
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
    prog/xdp id 48 tag 9cbab549c3af3eab jited
# ls /sys/fs/bpf/xdp/globals
jmp_tc  map_outer  map_sh
# bpftool map show
10: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
11: array  name map_inner  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
13: array_of_maps  name map_outer  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
14: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
48: xdp  name imain  tag 9cbab549c3af3eab  gpl
        loaded_at 2020-10-22T08:04:43-0400  uid 0
        xlated 224B  jited 139B  memlock 4096B  map_ids 14
        btf_id 60
# /root/iproute2/ip/ip link set veth0 xdp off
# rm -rf /sys/fs/bpf/xdp/globals


== Test load objs by tc
# /root/iproute2/tc/tc qdisc add dev veth0 ingress
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_cyclic.o sec 0xabccba/0
# /root/iproute2/tc/tc filter add dev veth0 parent ffff: bpf obj bpf_graft.o
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_tailcall.o sec 42/0
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_tailcall.o sec 42/1
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_tailcall.o sec 43/0
# /root/iproute2/tc/tc filter add dev veth0 ingress bpf da obj bpf_tailcall.o sec classifier
# /root/iproute2/ip/ip link show veth0
5: veth0@veth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 6a:e6:fa:2b:4e:1f brd ff:ff:ff:ff:ff:ff
# ls /sys/fs/bpf/xdp/37e88cb3b9646b2ea5f99ab31069ad88db06e73d /sys/fs/bpf/xdp/fc68fe3e96378a0cba284ea6acbe17e898d8b11f /sys/fs/bpf/xdp/globals
/sys/fs/bpf/xdp/37e88cb3b9646b2ea5f99ab31069ad88db06e73d:
jmp_tc

/sys/fs/bpf/xdp/fc68fe3e96378a0cba284ea6acbe17e898d8b11f:
jmp_ex  jmp_tc  map_sh

/sys/fs/bpf/xdp/globals:
jmp_tc
# bpftool map show
15: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
        owner_prog_type sched_cls  owner jited
16: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
        owner_prog_type sched_cls  owner jited
17: prog_array  name jmp_ex  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
        owner_prog_type sched_cls  owner jited
18: prog_array  name jmp_tc  flags 0x0
        key 4B  value 4B  max_entries 2  memlock 4096B
        owner_prog_type sched_cls  owner jited
19: array  name map_sh  flags 0x0
        key 4B  value 4B  max_entries 1  memlock 4096B
# bpftool prog show
52: sched_cls  name cls_loop  tag 3e98a40b04099d36  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 168B  jited 133B  memlock 4096B  map_ids 15
        btf_id 65
56: sched_cls  name cls_entry  tag 0fbb4d9310a6ee26  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 144B  jited 121B  memlock 4096B  map_ids 16
        btf_id 70
60: sched_cls  name cls_case1  tag e06a3bd62293d65d  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 328B  jited 216B  memlock 4096B  map_ids 19,17
        btf_id 75
66: sched_cls  name cls_case1  tag e06a3bd62293d65d  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 328B  jited 216B  memlock 4096B  map_ids 19,17
        btf_id 80
72: sched_cls  name cls_case1  tag e06a3bd62293d65d  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 328B  jited 216B  memlock 4096B  map_ids 19,17
        btf_id 85
78: sched_cls  name cls_case1  tag e06a3bd62293d65d  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 328B  jited 216B  memlock 4096B  map_ids 19,17
        btf_id 90
79: sched_cls  name cls_case2  tag ee218ff893dca823  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 336B  jited 218B  memlock 4096B  map_ids 19,18
        btf_id 90
80: sched_cls  name cls_exit  tag e78a58140deed387  gpl
        loaded_at 2020-10-22T08:04:45-0400  uid 0
        xlated 288B  jited 177B  memlock 4096B  map_ids 19
        btf_id 90

I also run the following upstream kselftest with patches iproute2 and
all passed.

test_lwt_ip_encap.sh
test_xdp_redirect.sh
test_tc_redirect.sh
test_xdp_meta.sh
test_xdp_veth.sh
test_xdp_vlan.sh

Hangbin Liu (5):
  configure: add check_libbpf() for later libbpf support
  lib: rename bpf.c to bpf_legacy.c
  lib: add libbpf support
  examples/bpf: move struct bpf_elf_map defined maps to legacy folder
  examples/bpf: add bpf examples with BTF defined maps

 configure                                |  48 ++++
 examples/bpf/README                      |  18 +-
 examples/bpf/bpf_graft.c                 |  14 +-
 examples/bpf/bpf_map_in_map.c            |  37 ++-
 examples/bpf/bpf_shared.c                |  14 +-
 examples/bpf/{ => legacy}/bpf_cyclic.c   |   2 +-
 examples/bpf/legacy/bpf_graft.c          |  66 +++++
 examples/bpf/legacy/bpf_map_in_map.c     |  56 ++++
 examples/bpf/legacy/bpf_shared.c         |  53 ++++
 examples/bpf/{ => legacy}/bpf_tailcall.c |   2 +-
 include/bpf_api.h                        |  13 +
 include/bpf_util.h                       |  17 +-
 ip/ipvrf.c                               |  19 +-
 lib/Makefile                             |   6 +-
 lib/{bpf.c => bpf_legacy.c}              | 184 ++++++++++++-
 lib/bpf_libbpf.c                         | 332 +++++++++++++++++++++++
 16 files changed, 833 insertions(+), 48 deletions(-)
 rename examples/bpf/{ => legacy}/bpf_cyclic.c (95%)
 create mode 100644 examples/bpf/legacy/bpf_graft.c
 create mode 100644 examples/bpf/legacy/bpf_map_in_map.c
 create mode 100644 examples/bpf/legacy/bpf_shared.c
 rename examples/bpf/{ => legacy}/bpf_tailcall.c (98%)
 rename lib/{bpf.c => bpf_legacy.c} (94%)
 create mode 100644 lib/bpf_libbpf.c

Alexei Starovoitov Oct. 28, 2020, 9:17 p.m. UTC | #2

On Wed, Oct 28, 2020 at 09:25:24PM +0800, Hangbin Liu wrote:
> This series converts iproute2 to use libbpf for loading and attaching
> BPF programs when it is available. This means that iproute2 will
> correctly process BTF information and support the new-style BTF-defined
> maps, while keeping compatibility with the old internal map definition
> syntax.
> 
> This is achieved by checking for libbpf at './configure' time, and using
> it if available. By default the system libbpf will be used, but static
> linking against a custom libbpf version can be achieved by passing
> LIBBPF_DIR to configure. FORCE_LIBBPF can be set to force configure to
> abort if no suitable libbpf is found (useful for automatic packaging
> that wants to enforce the dependency).
> 
> The old iproute2 bpf code is kept and will be used if no suitable libbpf
> is available. When using libbpf, wrapper code ensures that iproute2 will
> still understand the old map definition format, including populating
> map-in-map and tail call maps before load.
> 
> The examples in bpf/examples are kept, and a separate set of examples
> are added with BTF-based map definitions for those examples where this
> is possible (libbpf doesn't currently support declaratively populating
> tail call maps).

Awesome to see this work continue! Thank you.

Stephen Hemminger Nov. 29, 2020, 6:16 a.m. UTC | #3

On Fri, 23 Oct 2020 11:38:50 +0800
Hangbin Liu <haliu@redhat.com> wrote:

> This series converts iproute2 to use libbpf for loading and attaching
> BPF programs when it is available. This means that iproute2 will
> correctly process BTF information and support the new-style BTF-defined
> maps, while keeping compatibility with the old internal map definition
> syntax.
> 
> This is achieved by checking for libbpf at './configure' time, and using
> it if available. By default the system libbpf will be used, but static
> linking against a custom libbpf version can be achieved by passing
> LIBBPF_DIR to configure. FORCE_LIBBPF can be set to force configure to
> abort if no suitable libbpf is found (useful for automatic packaging
> that wants to enforce the dependency).
> 
> The old iproute2 bpf code is kept and will be used if no suitable libbpf
> is available. When using libbpf, wrapper code ensures that iproute2 will
> still understand the old map definition format, including populating
> map-in-map and tail call maps before load.
> 
> The examples in bpf/examples are kept, and a separate set of examples
> are added with BTF-based map definitions for those examples where this
> is possible (libbpf doesn't currently support declaratively populating
> tail call maps).


Luca wants to put this in Debian 11 (good idea), but that means:

1. It has to work with 5.10 release and kernel.
2. Someone has to test it.
3. The 5.10 is a LTS kernel release which means BPF developers have
   to agree to supporting LTS releases.

If someone steps up to doing this then I would be happy to merge it now
for 5.10. Otherwise it won't show up until 5.11.

Greg Kroah-Hartman Nov. 29, 2020, 6:22 a.m. UTC | #4

On Sat, Nov 28, 2020 at 10:16:35PM -0800, Stephen Hemminger wrote:
> On Fri, 23 Oct 2020 11:38:50 +0800
> Hangbin Liu <haliu@redhat.com> wrote:
> 
> > This series converts iproute2 to use libbpf for loading and attaching
> > BPF programs when it is available. This means that iproute2 will
> > correctly process BTF information and support the new-style BTF-defined
> > maps, while keeping compatibility with the old internal map definition
> > syntax.
> > 
> > This is achieved by checking for libbpf at './configure' time, and using
> > it if available. By default the system libbpf will be used, but static
> > linking against a custom libbpf version can be achieved by passing
> > LIBBPF_DIR to configure. FORCE_LIBBPF can be set to force configure to
> > abort if no suitable libbpf is found (useful for automatic packaging
> > that wants to enforce the dependency).
> > 
> > The old iproute2 bpf code is kept and will be used if no suitable libbpf
> > is available. When using libbpf, wrapper code ensures that iproute2 will
> > still understand the old map definition format, including populating
> > map-in-map and tail call maps before load.
> > 
> > The examples in bpf/examples are kept, and a separate set of examples
> > are added with BTF-based map definitions for those examples where this
> > is possible (libbpf doesn't currently support declaratively populating
> > tail call maps).
> 
> 
> Luca wants to put this in Debian 11 (good idea), but that means:
> 
> 1. It has to work with 5.10 release and kernel.
> 2. Someone has to test it.
> 3. The 5.10 is a LTS kernel release which means BPF developers have
>    to agree to supporting LTS releases.

Why would the bpf developers have to support any old releases?  That's
not their responsibility, that's the developers who want to create
stable/lts releases.

> If someone steps up to doing this then I would be happy to merge it now
> for 5.10. Otherwise it won't show up until 5.11.

Don't ever "rush" anything for a LTS/stable release, otherwise I am
going to have to go back to the old way of not announcing them until
_after_ they are released as people throw stuff that is not ready for
a normal merge.

This looks like a new feature, and shouldn't go in right now in the
development cycle anyway, all features for 5.10 had to be in linux-next
before 5.9 was released.

thanks,

greg k-h

Alexei Starovoitov Nov. 29, 2020, 5:33 p.m. UTC | #5

On Sat, Nov 28, 2020 at 10:16 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
>
> On Fri, 23 Oct 2020 11:38:50 +0800
> Hangbin Liu <haliu@redhat.com> wrote:
>
> > This series converts iproute2 to use libbpf for loading and attaching
> > BPF programs when it is available. This means that iproute2 will
> > correctly process BTF information and support the new-style BTF-defined
> > maps, while keeping compatibility with the old internal map definition
> > syntax.
> >
> > This is achieved by checking for libbpf at './configure' time, and using
> > it if available. By default the system libbpf will be used, but static
> > linking against a custom libbpf version can be achieved by passing
> > LIBBPF_DIR to configure. FORCE_LIBBPF can be set to force configure to
> > abort if no suitable libbpf is found (useful for automatic packaging
> > that wants to enforce the dependency).
> >
> > The old iproute2 bpf code is kept and will be used if no suitable libbpf
> > is available. When using libbpf, wrapper code ensures that iproute2 will
> > still understand the old map definition format, including populating
> > map-in-map and tail call maps before load.
> >
> > The examples in bpf/examples are kept, and a separate set of examples
> > are added with BTF-based map definitions for those examples where this
> > is possible (libbpf doesn't currently support declaratively populating
> > tail call maps).
>
>
> Luca wants to put this in Debian 11 (good idea), but that means:
>
> 1. It has to work with 5.10 release and kernel.
> 2. Someone has to test it.
> 3. The 5.10 is a LTS kernel release which means BPF developers have
>    to agree to supporting LTS releases.

That must be a bad joke.
You did the opposite of what we asked.
You folks are on your own.
5.10, 5.11 whatever release. When angry users come with questions
about random behavior you'll be answering them. Not us.

David Ahern Nov. 29, 2020, 7:41 p.m. UTC | #6

On 11/28/20 11:16 PM, Stephen Hemminger wrote:
> Luca wants to put this in Debian 11 (good idea), but that means:
> 
> 1. It has to work with 5.10 release and kernel.
> 2. Someone has to test it.
> 3. The 5.10 is a LTS kernel release which means BPF developers have
>    to agree to supporting LTS releases.
> 
> If someone steps up to doing this then I would be happy to merge it now
> for 5.10. Otherwise it won't show up until 5.11.

It would be good for Bullseye to have the option to use libbpf with
iproute2. If Debian uses the 5.10 kernel then it should use the 5.10
version of iproute2 and 5.10 version libbpf. All the components align
with consistent versioning.

I have some use cases I can move from bpftool loading to iproute2 as
additional testing to what Hangbin has already done. If that goes well,
I can re-send the patch series against iproute2-main branch by next weekend.

It would be good for others (Jesper, Toke, Jiri) to run their own
testing as well.

Toke Høiland-Jørgensen Nov. 30, 2020, 11:04 a.m. UTC | #7

David Ahern <dsahern@gmail.com> writes:

> On 11/28/20 11:16 PM, Stephen Hemminger wrote:
>> Luca wants to put this in Debian 11 (good idea), but that means:
>> 
>> 1. It has to work with 5.10 release and kernel.
>> 2. Someone has to test it.
>> 3. The 5.10 is a LTS kernel release which means BPF developers have
>>    to agree to supporting LTS releases.
>> 
>> If someone steps up to doing this then I would be happy to merge it now
>> for 5.10. Otherwise it won't show up until 5.11.
>
> It would be good for Bullseye to have the option to use libbpf with
> iproute2. If Debian uses the 5.10 kernel then it should use the 5.10
> version of iproute2 and 5.10 version libbpf. All the components align
> with consistent versioning.
>
> I have some use cases I can move from bpftool loading to iproute2 as
> additional testing to what Hangbin has already done. If that goes well,
> I can re-send the patch series against iproute2-main branch by next weekend.

This is fine by me - there's nothing in the iproute2 patches that
depends on any particular version of libbpf newer than 0.1.0 (that was
the whole point), so it's just a matter of when you guys want to merge
it.

> It would be good for others (Jesper, Toke, Jiri) to run their own
> testing as well.

I'll do some manual testing, and once we get this into RHEL it'll be
part of automated testing there as well. The latter may take a while,
though, so don't count on it for any initial verification...

-Toke

Michal Kubecek Nov. 30, 2020, 11:39 a.m. UTC | #8

On Sun, Nov 29, 2020 at 07:22:54AM +0100, Greg KH wrote:
> On Sat, Nov 28, 2020 at 10:16:35PM -0800, Stephen Hemminger wrote:
> 
> > If someone steps up to doing this then I would be happy to merge it now
> > for 5.10. Otherwise it won't show up until 5.11.
> 
> Don't ever "rush" anything for a LTS/stable release, otherwise I am
> going to have to go back to the old way of not announcing them until
> _after_ they are released as people throw stuff that is not ready for
> a normal merge.
> 
> This looks like a new feature, and shouldn't go in right now in the
> development cycle anyway, all features for 5.10 had to be in linux-next
> before 5.9 was released.

From the context, I believe Stephen meant merging into iproute2 5.10,
not kernel.

Michal Kubecek

Jesper Dangaard Brouer Dec. 1, 2020, 2:22 p.m. UTC | #9

On Sun, 29 Nov 2020 12:41:49 -0700
David Ahern <dsahern@gmail.com> wrote:

> On 11/28/20 11:16 PM, Stephen Hemminger wrote:
> > Luca wants to put this in Debian 11 (good idea), but that means:
> > 
> > 1. It has to work with 5.10 release and kernel.
> > 2. Someone has to test it.
> > 3. The 5.10 is a LTS kernel release which means BPF developers have
> >    to agree to supporting LTS releases.
> > 
> > If someone steps up to doing this then I would be happy to merge it now
> > for 5.10. Otherwise it won't show up until 5.11.  
> 
> It would be good for Bullseye to have the option to use libbpf with
> iproute2. If Debian uses the 5.10 kernel then it should use the 5.10
> version of iproute2 and 5.10 version libbpf. All the components align
> with consistent versioning.
> 
> I have some use cases I can move from bpftool loading to iproute2 as
> additional testing to what Hangbin has already done. If that goes well,
> I can re-send the patch series against iproute2-main branch by next weekend.
> 
> It would be good for others (Jesper, Toke, Jiri) to run their own
> testing as well.

I have tested this on a Ubuntu 20.04.1 LTS.

I had to compile tc my own "old" version (based it on iproute2 git
tree), because Ubuntu vendor tc util version didn't even support loading
BPF-ELF objects... weird!

Copy-pasted by compile instruction below signature (including one
failure, that people can find via Google search).

I tested difference combinations old vs. new loader with map pinning
and reuse of maps (as instructed by Toke over IRC), all the cases
worked.

I took it one step further and implemented tc libbpf detection:
 https://github.com/netoptimizer/bpf-examples/commit/048c960756eb65

So, my EDT-pacing code[1] now support BTF-maps, via configure detection
and code gets compiled with support, which allows me to inspect the
content really easily (data from production system):

$ bpftool map lookup id 1351 key 0x10 0x0 0x0 0x0
{
    "key": 16,
    "value": {
        "rate": 0,
        "t_last": 3299496947649930,
        "t_horizon_drop": 0,
        "t_horizon_ecn": 0,
        "codel": {
            "first_above_time": 3299496641781522,
            "drop_next": 3299497041788432,
            "count": 9,
            "dropping": 1
        }
    }
}

[1] https://github.com/netoptimizer/bpf-examples/tree/master/traffic-pacing-edt
- - 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer


Very recently iproute2 got support for using libbpf as BPF-ELF loader.

Testing this on Ubuntu 20.04.1 LTS.

Currently avail is iproute2-next tree:
- https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/
- git clone git://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git


First get libbpf:
  git clone https://github.com/libbpf/libbpf.git
  cd libbpf

Build libbpf and install it locally:

  cd ~/git/libbpf/
  mkdir build
  cd ~/git/libbpf/src
  DESTDIR=../build make install
  DESTDIR=../build make install_headers


Attempt#1: Try to get iproute2 compiling against:

  cd ~/git/iproute2-next
  $ LIBBPF_DIR=../libbpf/build/ ./configure 
  TC schedulers
   ATM	no
  
  libc has setns: yes
  SELinux support: no
  libbpf support: yes
  	libbpf version 0.3.0
  ELF support: yes
  libmnl support: yes
  Berkeley DB: no
  need for strlcpy: no
  libcap support: no

Make fails:
  $ make

  lib
      CC       bpf_libbpf.o
  bpf_libbpf.c:20:10: fatal error: bpf/libbpf.h: No such file or directory
     20 | #include <bpf/libbpf.h>
        |          ^~~~~~~~~~~~~~
  compilation terminated.


The problem is use of "relative path" in LIBBPF_DIR (../libbpf/build/), as
the Makefile enter subdir 'lib' and have these include path CFLAGS:

  CFLAGS += -DHAVE_LIBBPF  -I../libbpf/build//usr/include

Attempt#2 works: Try to get iproute2 compiling against:

  cd ~/git/iproute2-next
  $ LIBBPF_DIR=~/git/libbpf/build/ ./configure
  make


Install as stow version:

  export STOW=/usr/local/stow/iproute2-libbpf-next-git-c29f65db34
  make
  make PREFIX=$STOW SYSCONFDIR=$STOW CONFDIR=$STOW/etc/iproute2 SBINDIR=$STOW/sbin -n install
  make PREFIX=$STOW SYSCONFDIR=$STOW CONFDIR=$STOW/etc/iproute2 SBINDIR=$STOW/sbin install

Current state:
  $ tc -V
  tc utility, iproute2-5.9.0, libbpf 0.3.0

[iproute2-next,0/5] iproute2: add libbpf support

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