Sat Sep 24 2022 14:36:15 GMT+0100 (British Summer Time) ~ Hou Tao
<houtao@xxxxxxxxxxxxxxx>
> From: Hou Tao <houtao1@xxxxxxxxxx>
>
> Support lookup/update/delete/iterate/dump operations for qp-trie in
> bpftool. Mainly add two functions: one function to parse dynptr key and
> another one to dump dynptr key. The input format of dynptr key is:
> "key [hex] size BYTES" and the output format of dynptr key is:
> "size BYTES".
>
> The following is the output when using bpftool to manipulate
> qp-trie:
>
> $ bpftool map pin id 724953 /sys/fs/bpf/qp
> $ bpftool map show pinned /sys/fs/bpf/qp
> 724953: qp_trie name qp_trie flags 0x1
> key 16B value 4B max_entries 2 memlock 65536B map_extra 8
> btf_id 779
> pids test_qp_trie.bi(109167)
> $ bpftool map dump pinned /sys/fs/bpf/qp
> [{
> "key": {
> "size": 4,
> "data": ["0x0","0x0","0x0","0x0"
> ]
> },
> "value": 0
> },{
> "key": {
> "size": 4,
> "data": ["0x0","0x0","0x0","0x1"
> ]
> },
> "value": 2
> }
> ]
> $ bpftool map lookup pinned /sys/fs/bpf/qp key 4 0 0 0 1
> {
> "key": {
> "size": 4,
> "data": ["0x0","0x0","0x0","0x1"
> ]
> },
> "value": 2
> }
The bpftool patch looks good, thanks! I have one comment on the syntax
for the keys, I don't find it intuitive to have the size as the first
BYTE. It makes it awkward to understand what the command does if we read
it in the wild without knowing the map type. I can see two alternatives,
either adding a keyword (e.g., "key_size 4 key 0 0 0 1"), or changing
parse_bytes() to make it able to parse as much as it can then count the
bytes, when we don't know in advance how many we get.
Thanks,
Quentin
