From: Yonghong Song Date: Fri, 6 Jun 2025 16:31:46 +0000 (-0700) Subject: libbpf: Support link-based cgroup attach with options X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1d6711667cb358fd2971c760a67b4fe843179d15;p=thirdparty%2Fkernel%2Flinux.git libbpf: Support link-based cgroup attach with options Currently libbpf supports bpf_program__attach_cgroup() with signature: LIBBPF_API struct bpf_link * bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); To support mprog style attachment, additionsl fields like flags, relative_{fd,id} and expected_revision are needed. Add a new API: LIBBPF_API struct bpf_link * bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd, const struct bpf_cgroup_opts *opts); where bpf_cgroup_opts contains all above needed fields. Signed-off-by: Yonghong Song Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250606163146.2429212-1-yonghong.song@linux.dev --- diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index a9c3e33d0f8a9..6eb421ccf91bd 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -837,6 +837,50 @@ int bpf_link_create(int prog_fd, int target_fd, if (!OPTS_ZEROED(opts, netkit)) return libbpf_err(-EINVAL); break; + case BPF_CGROUP_INET_INGRESS: + case BPF_CGROUP_INET_EGRESS: + case BPF_CGROUP_INET_SOCK_CREATE: + case BPF_CGROUP_INET_SOCK_RELEASE: + case BPF_CGROUP_INET4_BIND: + case BPF_CGROUP_INET6_BIND: + case BPF_CGROUP_INET4_POST_BIND: + case BPF_CGROUP_INET6_POST_BIND: + case BPF_CGROUP_INET4_CONNECT: + case BPF_CGROUP_INET6_CONNECT: + case BPF_CGROUP_UNIX_CONNECT: + case BPF_CGROUP_INET4_GETPEERNAME: + case BPF_CGROUP_INET6_GETPEERNAME: + case BPF_CGROUP_UNIX_GETPEERNAME: + case BPF_CGROUP_INET4_GETSOCKNAME: + case BPF_CGROUP_INET6_GETSOCKNAME: + case BPF_CGROUP_UNIX_GETSOCKNAME: + case BPF_CGROUP_UDP4_SENDMSG: + case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_UNIX_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: + case BPF_CGROUP_UNIX_RECVMSG: + case BPF_CGROUP_SOCK_OPS: + case BPF_CGROUP_DEVICE: + case BPF_CGROUP_SYSCTL: + case BPF_CGROUP_GETSOCKOPT: + case BPF_CGROUP_SETSOCKOPT: + case BPF_LSM_CGROUP: + relative_fd = OPTS_GET(opts, cgroup.relative_fd, 0); + relative_id = OPTS_GET(opts, cgroup.relative_id, 0); + if (relative_fd && relative_id) + return libbpf_err(-EINVAL); + if (relative_id) { + attr.link_create.cgroup.relative_id = relative_id; + attr.link_create.flags |= BPF_F_ID; + } else { + attr.link_create.cgroup.relative_fd = relative_fd; + } + attr.link_create.cgroup.expected_revision = + OPTS_GET(opts, cgroup.expected_revision, 0); + if (!OPTS_ZEROED(opts, cgroup)) + return libbpf_err(-EINVAL); + 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 777627d33d257..1342564214c8b 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -438,6 +438,11 @@ struct bpf_link_create_opts { __u32 relative_id; __u64 expected_revision; } netkit; + struct { + __u32 relative_fd; + __u32 relative_id; + __u64 expected_revision; + } cgroup; }; size_t :0; }; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e9c641a2fb203..6445165a24f23 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -12837,6 +12837,34 @@ struct bpf_link *bpf_program__attach_xdp(const struct bpf_program *prog, int ifi return bpf_program_attach_fd(prog, ifindex, "xdp", NULL); } +struct bpf_link * +bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd, + const struct bpf_cgroup_opts *opts) +{ + LIBBPF_OPTS(bpf_link_create_opts, link_create_opts); + __u32 relative_id; + int relative_fd; + + if (!OPTS_VALID(opts, bpf_cgroup_opts)) + return libbpf_err_ptr(-EINVAL); + + relative_id = OPTS_GET(opts, relative_id, 0); + relative_fd = OPTS_GET(opts, relative_fd, 0); + + if (relative_fd && relative_id) { + pr_warn("prog '%s': relative_fd and relative_id cannot be set at the same time\n", + prog->name); + return libbpf_err_ptr(-EINVAL); + } + + link_create_opts.cgroup.expected_revision = OPTS_GET(opts, expected_revision, 0); + link_create_opts.cgroup.relative_fd = relative_fd; + link_create_opts.cgroup.relative_id = relative_id; + link_create_opts.flags = OPTS_GET(opts, flags, 0); + + return bpf_program_attach_fd(prog, cgroup_fd, "cgroup", &link_create_opts); +} + struct bpf_link * bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex, const struct bpf_tcx_opts *opts) diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 1137e7d2e1b5a..d1cf813a057bc 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -877,6 +877,21 @@ LIBBPF_API struct bpf_link * bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex, const struct bpf_netkit_opts *opts); +struct bpf_cgroup_opts { + /* size of this struct, for forward/backward compatibility */ + size_t sz; + __u32 flags; + __u32 relative_fd; + __u32 relative_id; + __u64 expected_revision; + size_t :0; +}; +#define bpf_cgroup_opts__last_field expected_revision + +LIBBPF_API struct bpf_link * +bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd, + const struct bpf_cgroup_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 1205f9a4fe048..c7fc0bde56486 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -437,6 +437,7 @@ LIBBPF_1.6.0 { bpf_linker__add_fd; bpf_linker__new_fd; bpf_object__prepare; + bpf_program__attach_cgroup_opts; bpf_program__func_info; bpf_program__func_info_cnt; bpf_program__line_info;