linux/tools/bpf
Prashant Bhole 8ec92dc22e tools/bpf: bpftool, print strerror when map lookup error occurs
Since map lookup error can be ENOENT or EOPNOTSUPP, let's print
strerror() as error message in normal and JSON output.

This patch adds helper function print_entry_error() to print
entry from lookup error occurs

Example: Following example dumps a map which does not support lookup.

Output before:
root# bpftool map -jp dump id 40
[
    "key": ["0x0a","0x00","0x00","0x00"
    ],
    "value": {
        "error": "can\'t lookup element"
    },
    "key": ["0x0b","0x00","0x00","0x00"
    ],
    "value": {
        "error": "can\'t lookup element"
    }
]

root# bpftool map dump id 40
can't lookup element with key:
0a 00 00 00
can't lookup element with key:
0b 00 00 00
Found 0 elements

Output after changes:
root# bpftool map dump -jp  id 45
[
    "key": ["0x0a","0x00","0x00","0x00"
    ],
    "value": {
        "error": "Operation not supported"
    },
    "key": ["0x0b","0x00","0x00","0x00"
    ],
    "value": {
        "error": "Operation not supported"
    }
]

root# bpftool map dump id 45
key:
0a 00 00 00
value:
Operation not supported
key:
0b 00 00 00
value:
Operation not supported
Found 0 elements

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-09 21:52:20 -07:00
..
bpftool tools/bpf: bpftool, print strerror when map lookup error occurs 2018-10-09 21:52:20 -07:00
.gitignore tools/bpftool: ignore build products 2018-07-26 02:50:26 +02:00
bpf_asm.c
bpf_dbg.c bpf: fix uninitialized variable in bpf tools 2018-04-26 22:23:02 +02:00
bpf_exp.l bpf: fix cbpf parser bug for octal numbers 2018-06-03 07:46:55 -07:00
bpf_exp.y
bpf_jit_disasm.c tools/bpf_jit_disasm: silence a static checker warning 2018-01-18 22:15:37 +01:00
Makefile bpf: fix for lex/yacc build error with gcc-5 2018-04-25 23:27:46 +02:00
Makefile.helpers tools: bpf: build and install man page for eBPF helpers from bpftool/ 2018-07-12 18:55:53 +02:00