On Sun, May 3, 2020 at 11:30 PM Yonghong Song <yhs@xxxxxx> wrote:
>
> Two bpf programs are added in this patch for netlink and ipv6_route
> target. On my VM, I am able to achieve identical
> results compared to /proc/net/netlink and /proc/net/ipv6_route.
>
> $ cat /proc/net/netlink
> sk Eth Pid Groups Rmem Wmem Dump Locks Drops Inode
> 000000002c42d58b 0 0 00000000 0 0 0 2 0 7
> 00000000a4e8b5e1 0 1 00000551 0 0 0 2 0 18719
> 00000000e1b1c195 4 0 00000000 0 0 0 2 0 16422
> 000000007e6b29f9 6 0 00000000 0 0 0 2 0 16424
> ....
> 00000000159a170d 15 1862 00000002 0 0 0 2 0 1886
> 000000009aca4bc9 15 3918224839 00000002 0 0 0 2 0 19076
> 00000000d0ab31d2 15 1 00000002 0 0 0 2 0 18683
> 000000008398fb08 16 0 00000000 0 0 0 2 0 27
> $ cat /sys/fs/bpf/my_netlink
> sk Eth Pid Groups Rmem Wmem Dump Locks Drops Inode
> 000000002c42d58b 0 0 00000000 0 0 0 2 0 7
> 00000000a4e8b5e1 0 1 00000551 0 0 0 2 0 18719
> 00000000e1b1c195 4 0 00000000 0 0 0 2 0 16422
> 000000007e6b29f9 6 0 00000000 0 0 0 2 0 16424
> ....
> 00000000159a170d 15 1862 00000002 0 0 0 2 0 1886
> 000000009aca4bc9 15 3918224839 00000002 0 0 0 2 0 19076
> 00000000d0ab31d2 15 1 00000002 0 0 0 2 0 18683
> 000000008398fb08 16 0 00000000 0 0 0 2 0 27
>
> $ cat /proc/net/ipv6_route
> fe800000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000001 00000000 00000001 eth0
> 00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo
> 00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000003 00000000 80200001 lo
> fe80000000000000c04b03fffe7827ce 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80200001 eth0
> ff000000000000000000000000000000 08 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000003 00000000 00000001 eth0
> 00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo
> $ cat /sys/fs/bpf/my_ipv6_route
> fe800000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000001 00000000 00000001 eth0
> 00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo
> 00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000003 00000000 80200001 lo
> fe80000000000000c04b03fffe7827ce 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80200001 eth0
> ff000000000000000000000000000000 08 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000003 00000000 00000001 eth0
> 00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo
>
> Signed-off-by: Yonghong Song <yhs@xxxxxx>
> ---
Looks good, but something weird with printf below...
Acked-by: Andrii Nakryiko <andriin@xxxxxx>
> .../selftests/bpf/progs/bpf_iter_ipv6_route.c | 63 ++++++++++++++++
> .../selftests/bpf/progs/bpf_iter_netlink.c | 74 +++++++++++++++++++
> 2 files changed, 137 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_ipv6_route.c
> create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_netlink.c
>
> diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_ipv6_route.c b/tools/testing/selftests/bpf/progs/bpf_iter_ipv6_route.c
> new file mode 100644
> index 000000000000..0dee4629298f
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/bpf_iter_ipv6_route.c
> @@ -0,0 +1,63 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2020 Facebook */
> +#include "vmlinux.h"
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +#include <bpf/bpf_endian.h>
> +
> +char _license[] SEC("license") = "GPL";
> +
> +extern bool CONFIG_IPV6_SUBTREES __kconfig __weak;
> +
> +#define RTF_GATEWAY 0x0002
> +#define IFNAMSIZ 16
nit: these look weirdly unaligned :)
> +#define fib_nh_gw_family nh_common.nhc_gw_family
> +#define fib_nh_gw6 nh_common.nhc_gw.ipv6
> +#define fib_nh_dev nh_common.nhc_dev
> +
[...]
> + dev = fib6_nh->fib_nh_dev;
> + if (dev)
> + BPF_SEQ_PRINTF(seq, "%08x %08x %08x %08x %8s\n", rt->fib6_metric,
> + rt->fib6_ref.refs.counter, 0, flags, dev->name);
> + else
> + BPF_SEQ_PRINTF(seq, "%08x %08x %08x %08x %8s\n", rt->fib6_metric,
> + rt->fib6_ref.refs.counter, 0, flags);
hmm... how does it work? you specify 4 params, but format string
expects 5. Shouldn't this fail?
> +
> + return 0;
> +}
> diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c b/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c
> new file mode 100644
> index 000000000000..0a85a621a36d
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c
> @@ -0,0 +1,74 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2020 Facebook */
> +#include "vmlinux.h"
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +#include <bpf/bpf_endian.h>
> +
> +char _license[] SEC("license") = "GPL";
> +
> +#define sk_rmem_alloc sk_backlog.rmem_alloc
> +#define sk_refcnt __sk_common.skc_refcnt
> +
> +#define offsetof(TYPE, MEMBER) ((size_t)&((TYPE *)0)->MEMBER)
> +#define container_of(ptr, type, member) \
> + ({ \
> + void *__mptr = (void *)(ptr); \
> + ((type *)(__mptr - offsetof(type, member))); \
> + })
we should probably put offsetof(), offsetofend() and container_of()
macro into bpf_helpers.h, seems like universal things for kernel
datastructs :)
[...]
