Implement tcx BPF link support for libbpf.
The bpf_program__attach_fd_opts() API has been refactored slightly in order to
pass bpf_link_create_opts pointer as input.
A new bpf_program__attach_tcx_opts() has been added on top of this which allows
for passing all relevant data via extensible struct bpf_tcx_opts.
The program sections tcx/ingress and tcx/egress correspond to the hook locations
for tc ingress and egress, respectively.
For concrete usage examples, see the extensive selftests that have been
developed as part of this series.
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
---
tools/lib/bpf/bpf.c | 5 +++++
tools/lib/bpf/bpf.h | 7 +++++++
tools/lib/bpf/libbpf.c | 44 +++++++++++++++++++++++++++++++++++-----
tools/lib/bpf/libbpf.h | 17 ++++++++++++++++
tools/lib/bpf/libbpf.map | 1 +
5 files changed, 69 insertions(+), 5 deletions(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index a3d1b7ebe224..c340d3cbc6bd 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -746,6 +746,11 @@ int bpf_link_create(int prog_fd, int target_fd,
if (!OPTS_ZEROED(opts, tracing))
return libbpf_err(-EINVAL);
break;
+ case BPF_TCX_INGRESS:
+ case BPF_TCX_EGRESS:
+ attr.link_create.tcx.relative_fd = OPTS_GET(opts, tcx.relative_fd, 0);
+ attr.link_create.tcx.expected_revision = OPTS_GET(opts, tcx.expected_revision, 0);
+ break;
default:
if (!OPTS_ZEROED(opts, flags))
return libbpf_err(-EINVAL);
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 480c584a6f7f..12591516dca0 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -370,6 +370,13 @@ struct bpf_link_create_opts {
struct {
__u64 cookie;
} tracing;
+ struct {
+ union {
+ __u32 relative_fd;
+ __u32 relative_id;
+ };
+ __u32 expected_revision;
+ } tcx;
};
size_t :0;
};
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b89127471c6a..d7b6ff49f02e 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -133,6 +133,7 @@ static const char * const link_type_name[] = {
[BPF_LINK_TYPE_KPROBE_MULTI] = "kprobe_multi",
[BPF_LINK_TYPE_STRUCT_OPS] = "struct_ops",
[BPF_LINK_TYPE_NETFILTER] = "netfilter",
+ [BPF_LINK_TYPE_TCX] = "tcx",
};
static const char * const map_type_name[] = {
@@ -11685,11 +11686,10 @@ static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_li
}
static struct bpf_link *
-bpf_program__attach_fd(const struct bpf_program *prog, int target_fd, int btf_id,
- const char *target_name)
+bpf_program__attach_fd_opts(const struct bpf_program *prog,
+ const struct bpf_link_create_opts *opts,
+ int target_fd, const char *target_name)
{
- DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts,
- .target_btf_id = btf_id);
enum bpf_attach_type attach_type;
char errmsg[STRERR_BUFSIZE];
struct bpf_link *link;
@@ -11707,7 +11707,7 @@ bpf_program__attach_fd(const struct bpf_program *prog, int target_fd, int btf_id
link->detach = &bpf_link__detach_fd;
attach_type = bpf_program__expected_attach_type(prog);
- link_fd = bpf_link_create(prog_fd, target_fd, attach_type, &opts);
+ link_fd = bpf_link_create(prog_fd, target_fd, attach_type, opts);
if (link_fd < 0) {
link_fd = -errno;
free(link);
@@ -11720,6 +11720,17 @@ bpf_program__attach_fd(const struct bpf_program *prog, int target_fd, int btf_id
return link;
}
+static struct bpf_link *
+bpf_program__attach_fd(const struct bpf_program *prog, int target_fd, int btf_id,
+ const char *target_name)
+{
+ LIBBPF_OPTS(bpf_link_create_opts, opts,
+ .target_btf_id = btf_id,
+ );
+
+ return bpf_program__attach_fd_opts(prog, &opts, target_fd, target_name);
+}
+
struct bpf_link *
bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd)
{
@@ -11738,6 +11749,29 @@ struct bpf_link *bpf_program__attach_xdp(const struct bpf_program *prog, int ifi
return bpf_program__attach_fd(prog, ifindex, 0, "xdp");
}
+struct bpf_link *
+bpf_program__attach_tcx_opts(const struct bpf_program *prog,
+ const struct bpf_tcx_opts *opts)
+{
+ LIBBPF_OPTS(bpf_link_create_opts, link_create_opts);
+ int ifindex = OPTS_GET(opts, ifindex, 0);
+
+ if (!OPTS_VALID(opts, bpf_tcx_opts))
+ return libbpf_err_ptr(-EINVAL);
+ if (!ifindex) {
+ pr_warn("prog '%s': target netdevice ifindex cannot be zero\n",
+ prog->name);
+ return libbpf_err_ptr(-EINVAL);
+ }
+
+ link_create_opts.tcx.expected_revision = OPTS_GET(opts, expected_revision, 0);
+ link_create_opts.tcx.relative_fd = OPTS_GET(opts, relative_fd, 0);
+ link_create_opts.flags = OPTS_GET(opts, flags, 0);
+
+ /* target_fd/target_ifindex use the same field in LINK_CREATE */
+ return bpf_program__attach_fd_opts(prog, &link_create_opts, ifindex, "tc");
+}
+
struct bpf_link *bpf_program__attach_freplace(const struct bpf_program *prog,
int target_fd,
const char *attach_func_name)
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 754da73c643b..8ffba0f67c60 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -718,6 +718,23 @@ LIBBPF_API struct bpf_link *
bpf_program__attach_freplace(const struct bpf_program *prog,
int target_fd, const char *attach_func_name);
+struct bpf_tcx_opts {
+ /* size of this struct, for forward/backward compatibility */
+ size_t sz;
+ int ifindex;
+ __u32 flags;
+ union {
+ __u32 relative_fd;
+ __u32 relative_id;
+ };
+ __u32 expected_revision;
+};
+#define bpf_tcx_opts__last_field expected_revision
+
+LIBBPF_API struct bpf_link *
+bpf_program__attach_tcx_opts(const struct bpf_program *prog,
+ const struct bpf_tcx_opts *opts);
+
struct bpf_map;
LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index a29b90e9713c..f66b714512c2 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -396,4 +396,5 @@ LIBBPF_1.3.0 {
global:
bpf_obj_pin_opts;
bpf_prog_detach_opts;
+ bpf_program__attach_tcx_opts;
} LIBBPF_1.2.0;
--
2.34.1
