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, 133 insertions, 0 deletions

diff --git a/tools/bpf/bpftool/Documentation/bpftool-net.rst b/tools/bpf/bpftool/Documentation/bpftool-net.rst
new file mode 100644
index 000000000000..48a61837a264
--- /dev/null
+++ b/tools/bpf/bpftool/Documentation/bpftool-net.rst
@@ -0,0 +1,133 @@
+================
+bpftool-net
+================
+-------------------------------------------------------------------------------
+tool for inspection of netdev/tc related bpf prog attachments
+-------------------------------------------------------------------------------
+
+:Manual section: 8
+
+SYNOPSIS
+========
+
+	**bpftool** [*OPTIONS*] **net** *COMMAND*
+
+	*OPTIONS* := { [{ **-j** | **--json** }] [{ **-p** | **--pretty** }] }
+
+	*COMMANDS* :=
+	{ **show** | **list** } [ **dev** name ] | **help**
+
+NET COMMANDS
+============
+
+|	**bpftool** **net { show | list } [ dev name ]**
+|	**bpftool** **net help**
+
+DESCRIPTION
+===========
+	**bpftool net { show | list } [ dev name ]**
+		  List all networking device driver and tc attachment in the system.
+
+                  Output will start with all xdp program attachment, followed by
+                  all tc class/qdisc bpf program attachments. Both xdp programs and
+                  tc programs are ordered based on ifindex number. If multiple bpf
+                  programs attached to the same networking device through **tc filter**,
+                  the order will be first all bpf programs attached to tc classes, then
+                  all bpf programs attached to non clsact qdiscs, and finally all
+                  bpf programs attached to root and clsact qdisc.
+
+	**bpftool net help**
+		  Print short help message.
+
+OPTIONS
+=======
+	-h, --help
+		  Print short generic help message (similar to **bpftool help**).
+
+	-v, --version
+		  Print version number (similar to **bpftool version**).
+
+	-j, --json
+		  Generate JSON output. For commands that cannot produce JSON, this
+		  option has no effect.
+
+	-p, --pretty
+		  Generate human-readable JSON output. Implies **-j**.
+
+EXAMPLES
+========
+
+| **# 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"
+                }
+            ]
+        }
+    ]
+
+
+SEE ALSO
+========
+	**bpftool**\ (8), **bpftool-prog**\ (8), **bpftool-map**\ (8)