On Wed, Nov 4, 2020 at 1:47 AM <mariusz.dudek@xxxxxxxxx> wrote:
>
> From: Mariusz Dudek <mariuszx.dudek@xxxxxxxxx>
>
> Add support for separation of eBPF program load and xsk socket
> creation.
>
> This is needed for use-case when you want to privide as little
> privileges as possible to the data plane application that will
> handle xsk socket creation and incoming traffic.
>
> With this patch the data entity container can be run with only
> CAP_NET_RAW capability to fulfill its purpose of creating xsk
> socket and handling packages. In case your umem is larger or
> equal process limit for MEMLOCK you need either increase the
> limit or CAP_IPC_LOCK capability.
>
> To resolve privileges issue two APIs are introduced:
>
> - xsk_setup_xdp_prog - prepares bpf program if given and
> loads it on a selected network interface or loads the built in
> XDP program, if no XDP program is supplied. It can also return
> xsks_map_fd which is needed by unprivileged process to update
> xsks_map with AF_XDP socket "fd"
>
> - xsk_update_xskmap - inserts an AF_XDP socket into an xskmap
> for a particular xsk_socket
>
Your commit message seems to be heavily shifted right...
> Signed-off-by: Mariusz Dudek <mariuszx.dudek@xxxxxxxxx>
> ---
> tools/lib/bpf/libbpf.map | 2 +
> tools/lib/bpf/xsk.c | 157 ++++++++++++++++++++++++++++++++-------
> tools/lib/bpf/xsk.h | 13 ++++
> 3 files changed, 146 insertions(+), 26 deletions(-)
>
[...]
> diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h
> index 1069c46364ff..c42b91935d3c 100644
> --- a/tools/lib/bpf/xsk.h
> +++ b/tools/lib/bpf/xsk.h
> @@ -201,6 +201,19 @@ struct xsk_umem_config {
> __u32 flags;
> };
>
> +struct bpf_prog_cfg {
> + struct bpf_insn *prog;
> + const char *license;
> + size_t insns_cnt;
> + int xsks_map_fd;
> +};
This config will have problems with backward/forward compatibility.
Please check how xxx_opts are done and use them for extensible options
structs.
> +
> +LIBBPF_API int xsk_setup_xdp_prog(int ifindex,
> + struct bpf_prog_cfg *cfg,
> + int *xsks_map_fd);
> +LIBBPF_API int xsk_update_xskmap(struct xsk_socket *xsk,
> + int xsks_map_fd);
this should be called xsk_socket__update_map? BTW, what's xskmap? Is
that a special BPF map type?
> +
> /* Flags for the libbpf_flags field. */
> #define XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD (1 << 0)
>
> --
> 2.20.1
>
