linux.git/tools/bpf/bpftool/net.c, branch for-next

bpftool: Fix undefined behavior in qsort(NULL, 0, ...)

2024-09-10T18:40:55+00:00

When netfilter has no entry to display, qsort is called with
qsort(NULL, 0, ...). This results in undefined behavior, as UBSan
reports:

net.c:827:2: runtime error: null pointer passed as argument 1, which is declared to never be null

Although the C standard does not explicitly state whether calling qsort
with a NULL pointer when the size is 0 constitutes undefined behavior,
Section 7.1.4 of the C standard (Use of library functions) mentions:

"Each of the following statements applies unless explicitly stated
otherwise in the detailed descriptions that follow: If an argument to a
function has an invalid value (such as a value outside the domain of
the function, or a pointer outside the address space of the program, or
a null pointer, or a pointer to non-modifiable storage when the
corresponding parameter is not const-qualified) or a type (after
promotion) not expected by a function with variable number of
arguments, the behavior is undefined."

To avoid this, add an early return when nf_link_info is NULL to prevent
calling qsort with a NULL pointer.

Signed-off-by: Kuan-Wei Chiu 
Signed-off-by: Andrii Nakryiko 
Reviewed-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20240910150207.3179306-1-visitorckw@gmail.com

bpftool: Fix undefined behavior caused by shifting into the sign bit

2024-09-09T22:57:09+00:00

Replace shifts of '1' with '1U' in bitwise operations within
__show_dev_tc_bpf() to prevent undefined behavior caused by shifting
into the sign bit of a signed integer. By using '1U', the operations
are explicitly performed on unsigned integers, avoiding potential
integer overflow or sign-related issues.

Signed-off-by: Kuan-Wei Chiu 
Signed-off-by: Andrii Nakryiko 
Acked-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20240908140009.3149781-1-visitorckw@gmail.com

bpftool: Add net attach/detach command to tcx prog

2024-07-29T19:54:00+00:00

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 
Signed-off-by: Daniel Borkmann 
Acked-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20240721144221.96228-1-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko

bpftool: Refactor xdp attach/detach type judgment

2024-07-29T19:53:50+00:00

This commit no logical changed, just increases code readability and
facilitates TCX prog expansion, which will be implemented in the next
patch.

Signed-off-by: Tao Chen 
Signed-off-by: Daniel Borkmann 
Acked-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20240721143353.95980-2-chen.dylane@gmail.com
Signed-off-by: Andrii Nakryiko

bpftool: Extend net dump with netkit progs

2023-10-24T23:07:32+00:00

Add support to dump BPF programs on netkit via bpftool. This includes both
the BPF link and attach ops programs. Dumped information contain the attach
location, function entry name, program ID and link ID when applicable.

Example with tc BPF link:

  # ./bpftool net
  xdp:

  tc:
  nk1(22) netkit/peer tc1 prog_id 43 link_id 12

  [...]

Example with json dump:

  # ./bpftool net --json | jq
  [
    {
      "xdp": [],
      "tc": [
        {
          "devname": "nk1",
          "ifindex": 18,
          "kind": "netkit/primary",
          "name": "tc1",
          "prog_id": 29,
          "prog_flags": [],
          "link_id": 8,
          "link_flags": []
        }
      ],
      "flow_dissector": [],
      "netfilter": []
    }
  ]

Signed-off-by: Daniel Borkmann 
Reviewed-by: Quentin Monnet 
Acked-by: Martin KaFai Lau 
Link: https://lore.kernel.org/r/20231024214904.29825-6-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau

bpftool: Extend net dump with tcx progs

2023-07-19T17:07:28+00:00

Add support to dump fd-based attach types via bpftool. This includes both
the tc BPF link and attach ops programs. Dumped information contain the
attach location, function entry name, program ID and link ID when applicable.

Example with tc BPF link:

  # ./bpftool net
  xdp:

  tc:
  bond0(4) tcx/ingress cil_from_netdev prog_id 784 link_id 10
  bond0(4) tcx/egress cil_to_netdev prog_id 804 link_id 11

  flow_dissector:

  netfilter:

Example with tc BPF attach ops:

  # ./bpftool net
  xdp:

  tc:
  bond0(4) tcx/ingress cil_from_netdev prog_id 654
  bond0(4) tcx/egress cil_to_netdev prog_id 672

  flow_dissector:

  netfilter:

Currently, permanent flags are not yet supported, so 'unknown' ones are dumped
via NET_DUMP_UINT_ONLY() and once we do have permanent ones, we dump them as
human readable string.

Signed-off-by: Daniel Borkmann 
Reviewed-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230719140858.13224-7-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov

tools: bpftool: print netfilter link info

2023-04-21T18:34:49+00:00

Dump protocol family, hook and priority value:
$ bpftool link
2: netfilter  prog 14
        ip input prio -128
        pids install(3264)
5: netfilter  prog 14
        ip6 forward prio 21
        pids a.out(3387)
9: netfilter  prog 14
        ip prerouting prio 123
        pids a.out(5700)
10: netfilter  prog 14
        ip input prio 21
        pids test2(5701)

v2: Quentin Monnet suggested to also add 'bpftool net' support:

$ bpftool net
xdp:

tc:

flow_dissector:

netfilter:

        ip prerouting prio 21 prog_id 14
        ip input prio -128 prog_id 14
        ip input prio 21 prog_id 14
        ip forward prio 21 prog_id 14
        ip output prio 21 prog_id 14
        ip postrouting prio 21 prog_id 14

'bpftool net' only dumps netfilter link type, links are sorted by protocol
family, hook and priority.

v5: fix bpf ci failure: libbpf needs small update to prog_type_name[]
    and probe_prog_load helper.
v4: don't fail with -EOPNOTSUPP in libbpf probe_prog_load, update
    prog_type_name[] with "netfilter" entry (bpf ci)
v3: fix bpf.h copy, 'reserved' member was removed (Alexei)
    use p_err, not fprintf (Quentin)

Suggested-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/eeeaac99-9053-90c2-aa33-cc1ecb1ae9ca@isovalent.com/
Reviewed-by: Quentin Monnet 
Signed-off-by: Florian Westphal 
Link: https://lore.kernel.org/r/20230421170300.24115-6-fw@strlen.de
Signed-off-by: Alexei Starovoitov

bpftool: Define _GNU_SOURCE only once

2022-10-25T17:11:56+00:00

_GNU_SOURCE is defined in several source files for bpftool, but only one
of them takes the precaution of checking whether the value is already
defined. Add #ifndef for other occurrences too.

This is in preparation for the support of disassembling JIT-ed programs
with LLVM, with $(llvm-config --cflags) passing -D_GNU_SOURCE as a
compilation argument.

Signed-off-by: Quentin Monnet 
Tested-by: Niklas Söderlund 
Acked-by: Song Liu 
Link: https://lore.kernel.org/r/20221025150329.97371-2-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov

bpftool: use new API for attaching XDP program

2022-01-21T05:22:02+00:00

Switch to new bpf_xdp_attach() API to avoid deprecation warnings.

Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/r/20220120061422.2710637-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov

tools: bpftool: Update and synchronise option list in doc and help msg

2021-07-30T22:40:27+00:00

All bpftool commands support the options for JSON output and debug from
libbpf. In addition, some commands support additional options
corresponding to specific use cases.

The list of options described in the man pages for the different
commands are not always accurate. The messages for interactive help are
mostly limited to HELP_SPEC_OPTIONS, and are even less representative of
the actual set of options supported for the commands.

Let's update the lists:

- HELP_SPEC_OPTIONS is modified to contain the "default" options (JSON
  and debug), and to be extensible (no ending curly bracket).
- All commands use HELP_SPEC_OPTIONS in their help message, and then
  complete the list with their specific options.
- The lists of options in the man pages are updated.
- The formatting of the list for bpftool.rst is adjusted to match
  formatting for the other man pages. This is for consistency, and also
  because it will be helpful in a future patch to automatically check
  that the files are synchronised.

Signed-off-by: Quentin Monnet 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20210730215435.7095-5-quentin@isovalent.com