bpftool: Add net attach/detach command to tcx prog

Now, attach/detach tcx prog supported in libbpf, so we can add new
command 'bpftool attach/detach tcx' to attach tcx prog with bpftool
for user.

 # bpftool prog load tc_prog.bpf.o /sys/fs/bpf/tc_prog
 # bpftool prog show
	...
	192: sched_cls  name tc_prog  tag 187aeb611ad00cfc  gpl
	loaded_at 2024-07-11T15:58:16+0800  uid 0
	xlated 152B  jited 97B  memlock 4096B  map_ids 100,99,97
	btf_id 260
 # bpftool net attach tcx_ingress name tc_prog dev lo
 # bpftool net
	...
	tc:
	lo(1) tcx/ingress tc_prog prog_id 29

 # bpftool net detach tcx_ingress dev lo
 # bpftool net
	...
	tc:
 # bpftool net attach tcx_ingress name tc_prog dev lo
 # bpftool net
	tc:
	lo(1) tcx/ingress tc_prog prog_id 29

Test environment: ubuntu_22_04, 6.7.0-060700-generic
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20240721144221.96228-1-chen.dylane@gmail.comSigned-off-by: Andrii Nakryiko <andrii@kernel.org>

tools/bpf/bpftool/net.c

@@ -67,6 +67,8 @@ enum net_attach_type {
 	NET_ATTACH_TYPE_XDP_GENERIC,
 	NET_ATTACH_TYPE_XDP_DRIVER,
 	NET_ATTACH_TYPE_XDP_OFFLOAD,
+	NET_ATTACH_TYPE_TCX_INGRESS,
+	NET_ATTACH_TYPE_TCX_EGRESS,
 };
 
 static const char * const attach_type_strings[] = {
@@ -74,6 +76,8 @@ static const char * const attach_type_strings[] = {
 	[NET_ATTACH_TYPE_XDP_GENERIC]	= "xdpgeneric",
 	[NET_ATTACH_TYPE_XDP_DRIVER]	= "xdpdrv",
 	[NET_ATTACH_TYPE_XDP_OFFLOAD]	= "xdpoffload",
+	[NET_ATTACH_TYPE_TCX_INGRESS]	= "tcx_ingress",
+	[NET_ATTACH_TYPE_TCX_EGRESS]	= "tcx_egress",
 };
 
 static const char * const attach_loc_strings[] = {
@@ -647,6 +651,32 @@ static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type,
 	return bpf_xdp_attach(ifindex, progfd, flags, NULL);
 }
 
+static int get_tcx_type(enum net_attach_type attach_type)
+{
+	switch (attach_type) {
+	case NET_ATTACH_TYPE_TCX_INGRESS:
+		return BPF_TCX_INGRESS;
+	case NET_ATTACH_TYPE_TCX_EGRESS:
+		return BPF_TCX_EGRESS;
+	default:
+		return -1;
+	}
+}
+
+static int do_attach_tcx(int progfd, enum net_attach_type attach_type, int ifindex)
+{
+	int type = get_tcx_type(attach_type);
+
+	return bpf_prog_attach(progfd, ifindex, type, 0);
+}
+
+static int do_detach_tcx(int targetfd, enum net_attach_type attach_type)
+{
+	int type = get_tcx_type(attach_type);
+
+	return bpf_prog_detach(targetfd, type);
+}
+
 static int do_attach(int argc, char **argv)
 {
 	enum net_attach_type attach_type;
@@ -692,6 +722,11 @@ static int do_attach(int argc, char **argv)
 	case NET_ATTACH_TYPE_XDP_OFFLOAD:
 		err = do_attach_detach_xdp(progfd, attach_type, ifindex, overwrite);
 		break;
+	/* attach tcx prog */
+	case NET_ATTACH_TYPE_TCX_INGRESS:
+	case NET_ATTACH_TYPE_TCX_EGRESS:
+		err = do_attach_tcx(progfd, attach_type, ifindex);
+		break;
 	default:
 		break;
 	}
@@ -738,6 +773,11 @@ static int do_detach(int argc, char **argv)
 		progfd = -1;
 		err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL);
 		break;
+	/* detach tcx prog */
+	case NET_ATTACH_TYPE_TCX_INGRESS:
+	case NET_ATTACH_TYPE_TCX_EGRESS:
+		err = do_detach_tcx(ifindex, attach_type);
+		break;
 	default:
 		break;
 	}
@@ -944,7 +984,8 @@ static int do_help(int argc, char **argv)
 		"       %1$s %2$s help\n"
 		"\n"
 		"       " HELP_SPEC_PROGRAM "\n"
-		"       ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n"
+		"       ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload | tcx_ingress\n"
+		"                        | tcx_egress }\n"
 		"       " HELP_SPEC_OPTIONS " }\n"
 		"\n"
 		"Note: Only xdp, tcx, tc, netkit, flow_dissector and netfilter attachments\n"