enum bpf_attach_type attach_type,
const struct bpf_link_create_opts *opts)
{
+ __u32 target_btf_id, iter_info_len;
union bpf_attr attr;
if (!OPTS_VALID(opts, bpf_link_create_opts))
return -EINVAL;
+ iter_info_len = OPTS_GET(opts, iter_info_len, 0);
+ target_btf_id = OPTS_GET(opts, target_btf_id, 0);
+
+ if (iter_info_len && target_btf_id)
+ return -EINVAL;
+
memset(&attr, 0, sizeof(attr));
attr.link_create.prog_fd = prog_fd;
attr.link_create.target_fd = target_fd;
attr.link_create.attach_type = attach_type;
attr.link_create.flags = OPTS_GET(opts, flags, 0);
- attr.link_create.iter_info =
- ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0));
- attr.link_create.iter_info_len = OPTS_GET(opts, iter_info_len, 0);
+
+ if (iter_info_len) {
+ attr.link_create.iter_info =
+ ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0));
+ attr.link_create.iter_info_len = iter_info_len;
+ } else if (target_btf_id) {
+ attr.link_create.target_btf_id = target_btf_id;
+ }
return sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr));
}
}
static struct bpf_link *
-bpf_program__attach_fd(struct bpf_program *prog, int target_fd,
+bpf_program__attach_fd(struct bpf_program *prog, int target_fd, int btf_id,
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;
link->detach = &bpf_link__detach_fd;
attach_type = bpf_program__get_expected_attach_type(prog);
- link_fd = bpf_link_create(prog_fd, target_fd, attach_type, NULL);
+ link_fd = bpf_link_create(prog_fd, target_fd, attach_type, &opts);
if (link_fd < 0) {
link_fd = -errno;
free(link);
struct bpf_link *
bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd)
{
- return bpf_program__attach_fd(prog, cgroup_fd, "cgroup");
+ return bpf_program__attach_fd(prog, cgroup_fd, 0, "cgroup");
}
struct bpf_link *
bpf_program__attach_netns(struct bpf_program *prog, int netns_fd)
{
- return bpf_program__attach_fd(prog, netns_fd, "netns");
+ return bpf_program__attach_fd(prog, netns_fd, 0, "netns");
}
struct bpf_link *bpf_program__attach_xdp(struct bpf_program *prog, int ifindex)
{
/* target_fd/target_ifindex use the same field in LINK_CREATE */
- return bpf_program__attach_fd(prog, ifindex, "xdp");
+ return bpf_program__attach_fd(prog, ifindex, 0, "xdp");
+}
+
+struct bpf_link *bpf_program__attach_freplace(struct bpf_program *prog,
+ int target_fd,
+ const char *attach_func_name)
+{
+ int btf_id;
+
+ if (!!target_fd != !!attach_func_name) {
+ pr_warn("prog '%s': supply none or both of target_fd and attach_func_name\n",
+ prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (prog->type != BPF_PROG_TYPE_EXT) {
+ pr_warn("prog '%s': only BPF_PROG_TYPE_EXT can attach as freplace",
+ prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (target_fd) {
+ btf_id = libbpf_find_prog_btf_id(attach_func_name, target_fd);
+ if (btf_id < 0)
+ return ERR_PTR(btf_id);
+
+ return bpf_program__attach_fd(prog, target_fd, btf_id, "freplace");
+ } else {
+ /* no target, so use raw_tracepoint_open for compatibility
+ * with old kernels
+ */
+ return bpf_program__attach_trace(prog);
+ }
}
struct bpf_link *