Commit 05c31b4a authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Martin KaFai Lau
Browse files

libbpf: Add link-based API for netkit 



This adds bpf_program__attach_netkit() API to libbpf. Overall it is very
similar to tcx. The API looks as following:

  LIBBPF_API struct bpf_link *
  bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
                             const struct bpf_netkit_opts *opts);

The struct bpf_netkit_opts is done in similar way as struct bpf_tcx_opts
for supporting bpf_mprog control parameters. The attach location for the
primary and peer device is derived from the program section "netkit/primary"
and "netkit/peer", respectively.

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20231024214904.29825-4-daniel@iogearbox.net


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 5c1b994d

tools/lib/bpf/bpf.c

+16 −0
Original line number Diff line number Diff line
@@ -810,6 +810,22 @@ int bpf_link_create(int prog_fd, int target_fd, 
		if (!OPTS_ZEROED(opts, tcx))

			return libbpf_err(-EINVAL);

		break;

	case BPF_NETKIT_PRIMARY:

	case BPF_NETKIT_PEER:

		relative_fd = OPTS_GET(opts, netkit.relative_fd, 0);

		relative_id = OPTS_GET(opts, netkit.relative_id, 0);

		if (relative_fd && relative_id)

			return libbpf_err(-EINVAL);

		if (relative_id) {

			attr.link_create.netkit.relative_id = relative_id;

			attr.link_create.flags |= BPF_F_ID;

		} else {

			attr.link_create.netkit.relative_fd = relative_fd;

		}

		attr.link_create.netkit.expected_revision = OPTS_GET(opts, netkit.expected_revision, 0);

		if (!OPTS_ZEROED(opts, netkit))

			return libbpf_err(-EINVAL);

		break;

	default:

		if (!OPTS_ZEROED(opts, flags))

			return libbpf_err(-EINVAL);

tools/lib/bpf/bpf.h

+5 −0
Original line number Diff line number Diff line
@@ -415,6 +415,11 @@ struct bpf_link_create_opts { 
			__u32 relative_id;

			__u64 expected_revision;

		} tcx;

		struct {

			__u32 relative_fd;

			__u32 relative_id;

			__u64 expected_revision;

		} netkit;

	};

	size_t :0;

};

tools/lib/bpf/libbpf.c

+39 −0
Original line number Diff line number Diff line
@@ -126,6 +126,8 @@ static const char * const attach_type_name[] = { 
	[BPF_TCX_INGRESS]		= "tcx_ingress",

	[BPF_TCX_EGRESS]		= "tcx_egress",

	[BPF_TRACE_UPROBE_MULTI]	= "trace_uprobe_multi",

	[BPF_NETKIT_PRIMARY]		= "netkit_primary",

	[BPF_NETKIT_PEER]		= "netkit_peer",

};



static const char * const link_type_name[] = {
@@ -142,6 +144,7 @@ static const char * const link_type_name[] = { 
	[BPF_LINK_TYPE_NETFILTER]		= "netfilter",

	[BPF_LINK_TYPE_TCX]			= "tcx",

	[BPF_LINK_TYPE_UPROBE_MULTI]		= "uprobe_multi",

	[BPF_LINK_TYPE_NETKIT]			= "netkit",

};



static const char * const map_type_name[] = {
@@ -8915,6 +8918,8 @@ static const struct bpf_sec_def section_defs[] = { 
	SEC_DEF("tc",			SCHED_CLS, 0, SEC_NONE), /* deprecated / legacy, use tcx */

	SEC_DEF("classifier",		SCHED_CLS, 0, SEC_NONE), /* deprecated / legacy, use tcx */

	SEC_DEF("action",		SCHED_ACT, 0, SEC_NONE), /* deprecated / legacy, use tcx */

	SEC_DEF("netkit/primary",	SCHED_CLS, BPF_NETKIT_PRIMARY, SEC_NONE),

	SEC_DEF("netkit/peer",		SCHED_CLS, BPF_NETKIT_PEER, SEC_NONE),

	SEC_DEF("tracepoint+",		TRACEPOINT, 0, SEC_NONE, attach_tp),

	SEC_DEF("tp+",			TRACEPOINT, 0, SEC_NONE, attach_tp),

	SEC_DEF("raw_tracepoint+",	RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
@@ -12126,6 +12131,40 @@ bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex, 
	return bpf_program_attach_fd(prog, ifindex, "tcx", &link_create_opts);

}



struct bpf_link *

bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,

			   const struct bpf_netkit_opts *opts)

{

	LIBBPF_OPTS(bpf_link_create_opts, link_create_opts);

	__u32 relative_id;

	int relative_fd;



	if (!OPTS_VALID(opts, bpf_netkit_opts))

		return libbpf_err_ptr(-EINVAL);



	relative_id = OPTS_GET(opts, relative_id, 0);

	relative_fd = OPTS_GET(opts, relative_fd, 0);



	/* validate we don't have unexpected combinations of non-zero fields */

	if (!ifindex) {

		pr_warn("prog '%s': target netdevice ifindex cannot be zero\n",

			prog->name);

		return libbpf_err_ptr(-EINVAL);

	}

	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.netkit.expected_revision = OPTS_GET(opts, expected_revision, 0);

	link_create_opts.netkit.relative_fd = relative_fd;

	link_create_opts.netkit.relative_id = relative_id;

	link_create_opts.flags = OPTS_GET(opts, flags, 0);



	return bpf_program_attach_fd(prog, ifindex, "netkit", &link_create_opts);

}



struct bpf_link *bpf_program__attach_freplace(const struct bpf_program *prog,

					      int target_fd,

					      const char *attach_func_name)

tools/lib/bpf/libbpf.h

+15 −0
Original line number Diff line number Diff line
@@ -800,6 +800,21 @@ LIBBPF_API struct bpf_link * 
bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,

			const struct bpf_tcx_opts *opts);



struct bpf_netkit_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_netkit_opts__last_field expected_revision



LIBBPF_API struct bpf_link *

bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,

			   const struct bpf_netkit_opts *opts);



struct bpf_map;



LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);

tools/lib/bpf/libbpf.map

+1 −0
Original line number Diff line number Diff line
@@ -398,6 +398,7 @@ LIBBPF_1.3.0 { 
		bpf_object__unpin;

		bpf_prog_detach_opts;

		bpf_program__attach_netfilter;

		bpf_program__attach_netkit;

		bpf_program__attach_tcx;

		bpf_program__attach_uprobe_multi;

		ring__avail_data_size;