[PATCH v5 bpf-next 08/11] libbpf: Add egress XDP support

[David Ahern]

From: David Ahern <dah...@digitalocean.com>

New section name hint, xdp_egress, is added to set expected attach
type at program load. Programs can use xdp_egress as the prefix in
the SEC statement to load the program with the BPF_XDP_EGRESS
attach type set.

egress_prog_id is added to xdp_link_info to report the program
id.

Signed-off-by: David Ahern <dah...@digitalocean.com>
---
 tools/lib/bpf/libbpf.c  | 2 ++
 tools/lib/bpf/libbpf.h  | 1 +
 tools/lib/bpf/netlink.c | 6 ++++++
 3 files changed, 9 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 3da66540b54b..5d1d513d9958 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6635,6 +6635,8 @@ static const struct bpf_sec_def section_defs[] = {
                .expected_attach_type = BPF_TRACE_ITER,
                .is_attach_btf = true,
                .attach_fn = attach_iter),
+       BPF_EAPROG_SEC("xdp_egress",            BPF_PROG_TYPE_XDP,
+                                               BPF_XDP_EGRESS),
        BPF_PROG_SEC("xdp",                     BPF_PROG_TYPE_XDP),
        BPF_PROG_SEC("perf_event",              BPF_PROG_TYPE_PERF_EVENT),
        BPF_PROG_SEC("lwt_in",                  BPF_PROG_TYPE_LWT_IN),
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 8ea69558f0a8..d3ded4b2da02 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -463,6 +463,7 @@ struct xdp_link_info {
        __u32 hw_prog_id;
        __u32 skb_prog_id;
        __u8 attach_mode;
+       __u32 egress_prog_id;
 };
 
 struct bpf_xdp_set_link_opts {
diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c
index 312f887570b2..da0b383dbd5d 100644
--- a/tools/lib/bpf/netlink.c
+++ b/tools/lib/bpf/netlink.c
@@ -280,6 +280,10 @@ static int get_xdp_info(void *cookie, void *msg, struct 
nlattr **tb)
                xdp_id->info.hw_prog_id = libbpf_nla_getattr_u32(
                        xdp_tb[IFLA_XDP_HW_PROG_ID]);
 
+       if (xdp_tb[IFLA_XDP_EGRESS_PROG_ID])
+               xdp_id->info.egress_prog_id = libbpf_nla_getattr_u32(
+                       xdp_tb[IFLA_XDP_EGRESS_PROG_ID]);
+
        return 0;
 }
 
@@ -331,6 +335,8 @@ static __u32 get_xdp_id(struct xdp_link_info *info, __u32 
flags)
                return info->hw_prog_id;
        if (flags & XDP_FLAGS_SKB_MODE)
                return info->skb_prog_id;
+       if (flags & XDP_FLAGS_EGRESS_MODE)
+               return info->egress_prog_id;
 
        return 0;
 }
-- 
2.21.1 (Apple Git-122.3)