4 Commits

Author SHA1 Message Date
Quentin Monnet
18841da981 tools: bpftool: Automate generation for "SEE ALSO" sections in man pages
The "SEE ALSO" sections of bpftool's manual pages refer to bpf(2),
bpf-helpers(7), then all existing bpftool man pages (save the current
one).

This leads to nearly-identical lists being duplicated in all manual
pages. Ideally, when a new page is created, all lists should be updated
accordingly, but this has led to omissions and inconsistencies multiple
times in the past.

Let's take it out of the RST files and generate the "SEE ALSO" sections
automatically in the Makefile when generating the man pages. The lists
are not really useful in the RST anyway because all other pages are
available in the same directory.

v3:
- Fix conflict with a previous patchset that introduced RST2MAN_OPTS
  variable passed to rst2man.

v2:
- Use "echo -n" instead of "printf" in Makefile, to avoid any risk of
  passing a format string directly to the command.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200910203935.25304-1-quentin@isovalent.com
2020-09-10 20:10:45 -07:00
Quentin Monnet
f28ef96d7b tools: bpftool: Include common options from separate file
Nearly all man pages for bpftool have the same common set of option
flags (--help, --version, --json, --pretty, --debug). The description is
duplicated across all the pages, which is more difficult to maintain if
the description of an option changes. It may also be confusing to sort
out what options are not "common" and should not be copied when creating
new manual pages.

Let's move the description for those common options to a separate file,
which is included with a RST directive when generating the man pages.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200909162500.17010-3-quentin@isovalent.com
2020-09-10 11:16:46 -07:00
Quentin Monnet
c8caa0bb4b tools, bpftool: Minor fixes for documentation
Bring minor improvements to bpftool documentation. Fix or harmonise
formatting, update map types (including in interactive help), improve
description for "map create", fix a build warning due to a missing line
after the double-colon for the "bpftool prog profile" example,
complete/harmonise/sort the list of related bpftool man pages in
footers.

v2:
- Remove (instead of changing) mark-up on "value" in bpftool-map.rst,
  when it does not refer to something passed on the command line.
- Fix an additional typo ("hexadeximal") in the same file.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200511161536.29853-3-quentin@isovalent.com
2020-05-11 21:20:50 +02:00
Martin KaFai Lau
65c9362859 bpftool: Add struct_ops support
This patch adds struct_ops support to the bpftool.

To recap a bit on the recent bpf_struct_ops feature on the kernel side:
It currently supports "struct tcp_congestion_ops" to be implemented
in bpf.  At a high level, bpf_struct_ops is struct_ops map populated
with a number of bpf progs.  bpf_struct_ops currently supports the
"struct tcp_congestion_ops".  However, the bpf_struct_ops design is
generic enough that other kernel struct ops can be supported in
the future.

Although struct_ops is map+progs at a high lever, there are differences
in details.  For example,
1) After registering a struct_ops, the struct_ops is held by the kernel
   subsystem (e.g. tcp-cc).  Thus, there is no need to pin a
   struct_ops map or its progs in order to keep them around.
2) To iterate all struct_ops in a system, it iterates all maps
   in type BPF_MAP_TYPE_STRUCT_OPS.  BPF_MAP_TYPE_STRUCT_OPS is
   the current usual filter.  In the future, it may need to
   filter by other struct_ops specific properties.  e.g. filter by
   tcp_congestion_ops or other kernel subsystem ops in the future.
3) struct_ops requires the running kernel having BTF info.  That allows
   more flexibility in handling other kernel structs.  e.g. it can
   always dump the latest bpf_map_info.
4) Also, "struct_ops" command is not intended to repeat all features
   already provided by "map" or "prog".  For example, if there really
   is a need to pin the struct_ops map, the user can use the "map" cmd
   to do that.

While the first attempt was to reuse parts from map/prog.c,  it ended up
not a lot to share.  The only obvious item is the map_parse_fds() but
that still requires modifications to accommodate struct_ops map specific
filtering (for the immediate and the future needs).  Together with the
earlier mentioned differences, it is better to part away from map/prog.c.

The initial set of subcmds are, register, unregister, show, and dump.

For register, it registers all struct_ops maps that can be found in an
obj file.  Option can be added in the future to specify a particular
struct_ops map.  Also, the common bpf_tcp_cc is stateless (e.g.
bpf_cubic.c and bpf_dctcp.c).  The "reuse map" feature is not
implemented in this patch and it can be considered later also.

For other subcmds, please see the man doc for details.

A sample output of dump:
[root@arch-fb-vm1 bpf]# bpftool struct_ops dump name cubic
[{
        "bpf_map_info": {
            "type": 26,
            "id": 64,
            "key_size": 4,
            "value_size": 256,
            "max_entries": 1,
            "map_flags": 0,
            "name": "cubic",
            "ifindex": 0,
            "btf_vmlinux_value_type_id": 18452,
            "netns_dev": 0,
            "netns_ino": 0,
            "btf_id": 52,
            "btf_key_type_id": 0,
            "btf_value_type_id": 0
        }
    },{
        "bpf_struct_ops_tcp_congestion_ops": {
            "refcnt": {
                "refs": {
                    "counter": 1
                }
            },
            "state": "BPF_STRUCT_OPS_STATE_INUSE",
            "data": {
                "list": {
                    "next": 0,
                    "prev": 0
                },
                "key": 0,
                "flags": 0,
                "init": "void (struct sock *) bictcp_init/prog_id:138",
                "release": "void (struct sock *) 0",
                "ssthresh": "u32 (struct sock *) bictcp_recalc_ssthresh/prog_id:141",
                "cong_avoid": "void (struct sock *, u32, u32) bictcp_cong_avoid/prog_id:140",
                "set_state": "void (struct sock *, u8) bictcp_state/prog_id:142",
                "cwnd_event": "void (struct sock *, enum tcp_ca_event) bictcp_cwnd_event/prog_id:139",
                "in_ack_event": "void (struct sock *, u32) 0",
                "undo_cwnd": "u32 (struct sock *) tcp_reno_undo_cwnd/prog_id:144",
                "pkts_acked": "void (struct sock *, const struct ack_sample *) bictcp_acked/prog_id:143",
                "min_tso_segs": "u32 (struct sock *) 0",
                "sndbuf_expand": "u32 (struct sock *) 0",
                "cong_control": "void (struct sock *, const struct rate_sample *) 0",
                "get_info": "size_t (struct sock *, u32, int *, union tcp_cc_info *) 0",
                "name": "bpf_cubic",
                "owner": 0
            }
        }
    }
]

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200318171656.129650-1-kafai@fb.com
2020-03-20 15:51:35 +01:00