Re: [PATCH bpf-next v2 1/3] bpftool: Add bpf_token show

[Tao Chen]

在 2025/7/22 23:01, Quentin Monnet 写道:
> 2025-07-22 19:58 UTC+0800 ~ Tao Chen <chen.dylane@xxxxxxxxx>
> > Add `bpftool token show` command to get token info
> > from bpffs in /proc/mounts.
> >
> > Example plain output for `token show`:
> > token_info  /sys/fs/bpf/token
> > 	allowed_cmds:
> > 	  map_create          prog_load
> > 	allowed_maps:
> > 	allowed_progs:
> > 	  kprobe
> > 	allowed_attachs:
> > 	  xdp
> > token_info  /sys/fs/bpf/token2
> > 	allowed_cmds:
> > 	  map_create          prog_load
> > 	allowed_maps:
> > 	allowed_progs:
> > 	  kprobe
> > 	allowed_attachs:
> > 	  xdp
> >
> > Example json output for `token show`:
> > [{
> > 	"token_info": "/sys/fs/bpf/token",
> > 	"allowed_cmds": ["map_create", "prog_load"],
> > 	"allowed_maps": [],
> > 	"allowed_progs": ["kprobe"],
> > 	"allowed_attachs": ["xdp"]
> > }, {
> > 	"token_info": "/sys/fs/bpf/token2",
> > 	"allowed_cmds": ["map_create", "prog_load"],
> > 	"allowed_maps": [],
> > 	"allowed_progs": ["kprobe"],
> > 	"allowed_attachs": ["xdp"]
> > }]
> >
> > Signed-off-by: Tao Chen <chen.dylane@xxxxxxxxx>
> > ---
>
> > diff --git a/tools/bpf/bpftool/token.c b/tools/bpf/bpftool/token.c
> > new file mode 100644
> > index 00000000000..f72a116f9c6
> > --- /dev/null
> > +++ b/tools/bpf/bpftool/token.c
>
> > +static int show_token_info(void)
> > +{
> > +	FILE *fp;
> > +	struct mntent *ent;
> > +	bool hit = false;
> > +
> > +	fp = setmntent(MOUNTS_FILE, "r");
> > +	if (!fp) {
> > +		p_err("Failed to open: %s", MOUNTS_FILE);
> > +		return -1;
> > +	}
> > +
> > +	if (json_output)
> > +		jsonw_start_array(json_wtr);
> > +
> > +	while ((ent = getmntent(fp)) != NULL) {
> > +		if (strncmp(ent->mnt_type, "bpf", 3) == 0) {
> > +			if (has_delegate_options(ent->mnt_opts)) {
> > +				__show_token_info(ent);
> > +				hit = true;
> > +			}
> > +		}
> > +	}
> > +
> > +	if (json_output)
> > +		jsonw_end_array(json_wtr);
> > +
> > +	if (!hit)
> > +		p_info("Token info not found");
>
> Woops I take this one back. It made sense to have a p_info() message in
> your v1 because you were only looking at one bpffs mount point, but now
> we list all the ones we find, we should remove this message and silently
> ignore mount points without token info (and I think we can remove the
> "hit" variable entirely). Sorry! :)

It‘s okay, i will remove it in v3, thanks anyway.

> The rest of this patch looks good to me, thank you
>
> Quentin


--
Best Regards
Tao Chen