tools/bpf: bpftool: add net support

Add "bpftool net" support. Networking devices are enumerated
to dump device index/name associated with xdp progs.

For each networking device, tc classes and qdiscs are enumerated
in order to check their bpf filters.
In addition, root handle and clsact ingress/egress are also checked for
bpf filters.  Not all filter information is printed out. Only ifindex,
kind, filter name, prog_id and tag are printed out, which are good
enough to show attachment information. If the filter action
is a bpf action, its bpf program id, bpf name and tag will be
printed out as well.

For example,
  $ ./bpftool net
  xdp [
  ifindex 2 devname eth0 prog_id 198
  ]
  tc_filters [
  ifindex 2 kind qdisc_htb name prefix_matcher.o:[cls_prefix_matcher_htb]
            prog_id 111727 tag d08fe3b4319bc2fd act []
  ifindex 2 kind qdisc_clsact_ingress name fbflow_icmp
            prog_id 130246 tag 3f265c7f26db62c9 act []
  ifindex 2 kind qdisc_clsact_egress name prefix_matcher.o:[cls_prefix_matcher_clsact]
            prog_id 111726 tag 99a197826974c876
  ifindex 2 kind qdisc_clsact_egress name cls_fg_dscp
            prog_id 108619 tag dc4630674fd72dcc act []
  ifindex 2 kind qdisc_clsact_egress name fbflow_egress
            prog_id 130245 tag 72d2d830d6888d2c
  ]
  $ ./bpftool -jp net
  [{
        "xdp": [{
                "ifindex": 2,
                "devname": "eth0",
                "prog_id": 198
            }
        ],
        "tc_filters": [{
                "ifindex": 2,
                "kind": "qdisc_htb",
                "name": "prefix_matcher.o:[cls_prefix_matcher_htb]",
                "prog_id": 111727,
                "tag": "d08fe3b4319bc2fd",
                "act": []
            },{
                "ifindex": 2,
                "kind": "qdisc_clsact_ingress",
                "name": "fbflow_icmp",
                "prog_id": 130246,
                "tag": "3f265c7f26db62c9",
                "act": []
            },{
                "ifindex": 2,
                "kind": "qdisc_clsact_egress",
                "name": "prefix_matcher.o:[cls_prefix_matcher_clsact]",
                "prog_id": 111726,
                "tag": "99a197826974c876"
            },{
                "ifindex": 2,
                "kind": "qdisc_clsact_egress",
                "name": "cls_fg_dscp",
                "prog_id": 108619,
                "tag": "dc4630674fd72dcc",
                "act": []
            },{
                "ifindex": 2,
                "kind": "qdisc_clsact_egress",
                "name": "fbflow_egress",
                "prog_id": 130245,
                "tag": "72d2d830d6888d2c"
            }
        ]
    }
  ]

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 103 insertions, 0 deletions

diff --git a/tools/bpf/bpftool/netlink_dumper.h b/tools/bpf/bpftool/netlink_dumper.h
new file mode 100644
index 000000000000..552d8851ac06
--- /dev/null
+++ b/tools/bpf/bpftool/netlink_dumper.h
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright (C) 2018 Facebook
+
+#ifndef _NETLINK_DUMPER_H_
+#define _NETLINK_DUMPER_H_
+
+#define NET_START_OBJECT				\
+{							\
+	if (json_output)				\
+		jsonw_start_object(json_wtr);		\
+}
+
+#define NET_START_OBJECT_NESTED(name)			\
+{							\
+	if (json_output) {				\
+		jsonw_name(json_wtr, name);		\
+		jsonw_start_object(json_wtr);		\
+	} else {					\
+		fprintf(stderr, "%s {", name);		\
+	}						\
+}
+
+#define NET_START_OBJECT_NESTED2			\
+{							\
+	if (json_output)				\
+		jsonw_start_object(json_wtr);		\
+	else						\
+		fprintf(stderr, "{");			\
+}
+
+#define NET_END_OBJECT_NESTED				\
+{							\
+	if (json_output)				\
+		jsonw_end_object(json_wtr);		\
+	else						\
+		fprintf(stderr, "}");			\
+}
+
+#define NET_END_OBJECT					\
+{							\
+	if (json_output)				\
+		jsonw_end_object(json_wtr);		\
+}
+
+#define NET_END_OBJECT_FINAL				\
+{							\
+	if (json_output)				\
+		jsonw_end_object(json_wtr);		\
+	else						\
+		fprintf(stderr, "\n");			\
+}
+
+#define NET_START_ARRAY(name, newline)			\
+{							\
+	if (json_output) {				\
+		jsonw_name(json_wtr, name);		\
+		jsonw_start_array(json_wtr);		\
+	} else {					\
+		fprintf(stderr, "%s [%s", name, newline);\
+	}						\
+}
+
+#define NET_END_ARRAY(endstr)				\
+{							\
+	if (json_output)				\
+		jsonw_end_array(json_wtr);		\
+	else						\
+		fprintf(stderr, "]%s", endstr);		\
+}
+
+#define NET_DUMP_UINT(name, val)			\
+{							\
+	if (json_output)				\
+		jsonw_uint_field(json_wtr, name, val);	\
+	else						\
+		fprintf(stderr, "%s %d ", name, val);	\
+}
+
+#define NET_DUMP_LLUINT(name, val)			\
+{							\
+	if (json_output)				\
+		jsonw_lluint_field(json_wtr, name, val);\
+	else						\
+		fprintf(stderr, "%s %lld ", name, val);	\
+}
+
+#define NET_DUMP_STR(name, str)				\
+{							\
+	if (json_output)				\
+		jsonw_string_field(json_wtr, name, str);\
+	else						\
+		fprintf(stderr, "%s %s ", name, str);	\
+}
+
+#define NET_DUMP_STR_ONLY(str)				\
+{							\
+	if (json_output)				\
+		jsonw_string(json_wtr, str);		\
+	else						\
+		fprintf(stderr, "%s ", str);		\
+}
+
+#endif