2022-08-29 23:45:30

by Hao Luo

[permalink] [raw]
Subject: [PATCH bpf-next v1] bpftool: Add support for querying cgroup_iter link

Support dumping info of a cgroup_iter link. This includes
showing the cgroup's id and the order for walking the cgroup
hierarchy. Example output is as follows:

> bpftool link show
1: iter prog 2 target_name bpf_map
2: iter prog 3 target_name bpf_prog
3: iter prog 12 target_name cgroup cgroup_id 72 order self_only

> bpftool -p link show
[{
"id": 1,
"type": "iter",
"prog_id": 2,
"target_name": "bpf_map"
},{
"id": 2,
"type": "iter",
"prog_id": 3,
"target_name": "bpf_prog"
},{
"id": 3,
"type": "iter",
"prog_id": 12,
"target_name": "cgroup",
"cgroup_id": 72,
"order": "self_only"
}
]

Signed-off-by: Hao Luo <[email protected]>
---
tools/bpf/bpftool/link.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)

diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
index 7a20931c3250..9e8d14d0114d 100644
--- a/tools/bpf/bpftool/link.c
+++ b/tools/bpf/bpftool/link.c
@@ -83,6 +83,29 @@ static bool is_iter_map_target(const char *target_name)
strcmp(target_name, "bpf_sk_storage_map") == 0;
}

+static bool is_iter_cgroup_target(const char *target_name)
+{
+ return strcmp(target_name, "cgroup") == 0;
+}
+
+static const char *cgroup_order_string(__u32 order)
+{
+ switch (order) {
+ case BPF_CGROUP_ITER_ORDER_UNSPEC:
+ return "order_unspec";
+ case BPF_CGROUP_ITER_SELF_ONLY:
+ return "self_only";
+ case BPF_CGROUP_ITER_DESCENDANTS_PRE:
+ return "descendants_pre";
+ case BPF_CGROUP_ITER_DESCENDANTS_POST:
+ return "descendants_post";
+ case BPF_CGROUP_ITER_ANCESTORS_UP:
+ return "ancestors_up";
+ default: /* won't happen */
+ return "";
+ }
+}
+
static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
{
const char *target_name = u64_to_ptr(info->iter.target_name);
@@ -91,6 +114,12 @@ static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)

if (is_iter_map_target(target_name))
jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
+
+ if (is_iter_cgroup_target(target_name)) {
+ jsonw_lluint_field(wtr, "cgroup_id", info->iter.cgroup.cgroup_id);
+ jsonw_string_field(wtr, "order",
+ cgroup_order_string(info->iter.cgroup.order));
+ }
}

static int get_prog_info(int prog_id, struct bpf_prog_info *info)
@@ -208,6 +237,12 @@ static void show_iter_plain(struct bpf_link_info *info)

if (is_iter_map_target(target_name))
printf("map_id %u ", info->iter.map.map_id);
+
+ if (is_iter_cgroup_target(target_name)) {
+ printf("cgroup_id %llu ", info->iter.cgroup.cgroup_id);
+ printf("order %s ",
+ cgroup_order_string(info->iter.cgroup.order));
+ }
}

static int show_link_close_plain(int fd, struct bpf_link_info *info)
--
2.37.2.672.g94769d06f0-goog


2022-08-30 13:40:57

by Quentin Monnet

[permalink] [raw]
Subject: Re: [PATCH bpf-next v1] bpftool: Add support for querying cgroup_iter link

On 30/08/2022 00:18, Hao Luo wrote:
> Support dumping info of a cgroup_iter link. This includes
> showing the cgroup's id and the order for walking the cgroup
> hierarchy. Example output is as follows:
>
>> bpftool link show
> 1: iter prog 2 target_name bpf_map
> 2: iter prog 3 target_name bpf_prog
> 3: iter prog 12 target_name cgroup cgroup_id 72 order self_only
>
>> bpftool -p link show
> [{
> "id": 1,
> "type": "iter",
> "prog_id": 2,
> "target_name": "bpf_map"
> },{
> "id": 2,
> "type": "iter",
> "prog_id": 3,
> "target_name": "bpf_prog"
> },{
> "id": 3,
> "type": "iter",
> "prog_id": 12,
> "target_name": "cgroup",
> "cgroup_id": 72,
> "order": "self_only"
> }
> ]
>
> Signed-off-by: Hao Luo <[email protected]>
> ---
> tools/bpf/bpftool/link.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
> index 7a20931c3250..9e8d14d0114d 100644
> --- a/tools/bpf/bpftool/link.c
> +++ b/tools/bpf/bpftool/link.c
> @@ -83,6 +83,29 @@ static bool is_iter_map_target(const char *target_name)
> strcmp(target_name, "bpf_sk_storage_map") == 0;
> }
>
> +static bool is_iter_cgroup_target(const char *target_name)
> +{
> + return strcmp(target_name, "cgroup") == 0;
> +}
> +
> +static const char *cgroup_order_string(__u32 order)
> +{
> + switch (order) {
> + case BPF_CGROUP_ITER_ORDER_UNSPEC:
> + return "order_unspec";
> + case BPF_CGROUP_ITER_SELF_ONLY:
> + return "self_only";
> + case BPF_CGROUP_ITER_DESCENDANTS_PRE:
> + return "descendants_pre";
> + case BPF_CGROUP_ITER_DESCENDANTS_POST:
> + return "descendants_post";
> + case BPF_CGROUP_ITER_ANCESTORS_UP:
> + return "ancestors_up";
> + default: /* won't happen */
> + return "";

I wonder if that one should be "unknown", in case another option is
added in the future, so we can spot it and address it?

> + }
> +}
> +
> static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
> {
> const char *target_name = u64_to_ptr(info->iter.target_name);
> @@ -91,6 +114,12 @@ static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
>
> if (is_iter_map_target(target_name))
> jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
> +
> + if (is_iter_cgroup_target(target_name)) {
> + jsonw_lluint_field(wtr, "cgroup_id", info->iter.cgroup.cgroup_id);
> + jsonw_string_field(wtr, "order",
> + cgroup_order_string(info->iter.cgroup.order));
> + }
> }
>
> static int get_prog_info(int prog_id, struct bpf_prog_info *info)
> @@ -208,6 +237,12 @@ static void show_iter_plain(struct bpf_link_info *info)
>
> if (is_iter_map_target(target_name))
> printf("map_id %u ", info->iter.map.map_id);
> +
> + if (is_iter_cgroup_target(target_name)) {
> + printf("cgroup_id %llu ", info->iter.cgroup.cgroup_id);
> + printf("order %s ",
> + cgroup_order_string(info->iter.cgroup.order));
> + }
> }
>
> static int show_link_close_plain(int fd, struct bpf_link_info *info)

Looks good to me, thank you!

Reviewed-by: Quentin Monnet <[email protected]>

2022-08-30 16:49:07

by Yonghong Song

[permalink] [raw]
Subject: Re: [PATCH bpf-next v1] bpftool: Add support for querying cgroup_iter link



On 8/29/22 4:18 PM, Hao Luo wrote:
> Support dumping info of a cgroup_iter link. This includes
> showing the cgroup's id and the order for walking the cgroup
> hierarchy. Example output is as follows:
>
>> bpftool link show
> 1: iter prog 2 target_name bpf_map
> 2: iter prog 3 target_name bpf_prog
> 3: iter prog 12 target_name cgroup cgroup_id 72 order self_only
>
>> bpftool -p link show
> [{
> "id": 1,
> "type": "iter",
> "prog_id": 2,
> "target_name": "bpf_map"
> },{
> "id": 2,
> "type": "iter",
> "prog_id": 3,
> "target_name": "bpf_prog"
> },{
> "id": 3,
> "type": "iter",
> "prog_id": 12,
> "target_name": "cgroup",
> "cgroup_id": 72,
> "order": "self_only"
> }
> ]
>
> Signed-off-by: Hao Luo <[email protected]>

Acked-by: Yonghong Song <[email protected]>

2022-08-30 18:27:28

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH bpf-next v1] bpftool: Add support for querying cgroup_iter link

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Martin KaFai Lau <[email protected]>:

On Mon, 29 Aug 2022 16:18:28 -0700 you wrote:
> Support dumping info of a cgroup_iter link. This includes
> showing the cgroup's id and the order for walking the cgroup
> hierarchy. Example output is as follows:
>
> > bpftool link show
> 1: iter prog 2 target_name bpf_map
> 2: iter prog 3 target_name bpf_prog
> 3: iter prog 12 target_name cgroup cgroup_id 72 order self_only
>
> [...]

Here is the summary with links:
- [bpf-next,v1] bpftool: Add support for querying cgroup_iter link
https://git.kernel.org/bpf/bpf-next/c/6f95de6d7131

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html


2022-08-30 18:31:49

by Martin KaFai Lau

[permalink] [raw]
Subject: Re: [PATCH bpf-next v1] bpftool: Add support for querying cgroup_iter link

On Tue, Aug 30, 2022 at 02:33:47PM +0100, Quentin Monnet wrote:
> > +static const char *cgroup_order_string(__u32 order)
> > +{
> > + switch (order) {
> > + case BPF_CGROUP_ITER_ORDER_UNSPEC:
> > + return "order_unspec";
> > + case BPF_CGROUP_ITER_SELF_ONLY:
> > + return "self_only";
> > + case BPF_CGROUP_ITER_DESCENDANTS_PRE:
> > + return "descendants_pre";
> > + case BPF_CGROUP_ITER_DESCENDANTS_POST:
> > + return "descendants_post";
> > + case BPF_CGROUP_ITER_ANCESTORS_UP:
> > + return "ancestors_up";
> > + default: /* won't happen */
> > + return "";
>
> I wonder if that one should be "unknown", in case another option is
> added in the future, so we can spot it and address it?
I added "unknown" and applied.

2022-08-30 18:37:38

by Hao Luo

[permalink] [raw]
Subject: Re: [PATCH bpf-next v1] bpftool: Add support for querying cgroup_iter link

On Tue, Aug 30, 2022 at 11:06 AM Martin KaFai Lau <[email protected]> wrote:
>
> On Tue, Aug 30, 2022 at 02:33:47PM +0100, Quentin Monnet wrote:
> > > +static const char *cgroup_order_string(__u32 order)
> > > +{
> > > + switch (order) {
> > > + case BPF_CGROUP_ITER_ORDER_UNSPEC:
> > > + return "order_unspec";
> > > + case BPF_CGROUP_ITER_SELF_ONLY:
> > > + return "self_only";
> > > + case BPF_CGROUP_ITER_DESCENDANTS_PRE:
> > > + return "descendants_pre";
> > > + case BPF_CGROUP_ITER_DESCENDANTS_POST:
> > > + return "descendants_post";
> > > + case BPF_CGROUP_ITER_ANCESTORS_UP:
> > > + return "ancestors_up";
> > > + default: /* won't happen */
> > > + return "";
> >
> > I wonder if that one should be "unknown", in case another option is
> > added in the future, so we can spot it and address it?
> I added "unknown" and applied.

Thanks Martin and Quentin, "unknown" is better than an empty string.

2022-08-30 19:02:20

by Hao Luo

[permalink] [raw]
Subject: Re: [PATCH bpf-next v1] bpftool: Add support for querying cgroup_iter link

On Tue, Aug 30, 2022 at 9:41 AM Yonghong Song <[email protected]> wrote:
>
> On 8/29/22 4:18 PM, Hao Luo wrote:
[...]
> >
> > Signed-off-by: Hao Luo <[email protected]>
>
> Acked-by: Yonghong Song <[email protected]>

Thanks Yonghong.