* [PATCH bpf-next v4 1/3] bpf: implement link_query for bpf iterators
2020-08-21 18:44 [PATCH bpf-next v4 0/3] bpf: implement link_query for bpf iterators Yonghong Song
@ 2020-08-21 18:44 ` Yonghong Song
2020-08-21 18:44 ` [PATCH bpf-next v4 2/3] bpf: implement link_query callbacks in map element iterators Yonghong Song
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Yonghong Song @ 2020-08-21 18:44 UTC (permalink / raw)
To: bpf, netdev; +Cc: Alexei Starovoitov, Daniel Borkmann, kernel-team
This patch implemented bpf_link callback functions
show_fdinfo and fill_link_info to support link_query
interface.
The general interface for show_fdinfo and fill_link_info
will print/fill the target_name. Each targets can
register show_fdinfo and fill_link_info callbacks
to print/fill more target specific information.
For example, the below is a fdinfo result for a bpf
task iterator.
$ cat /proc/1749/fdinfo/7
pos: 0
flags: 02000000
mnt_id: 14
link_type: iter
link_id: 11
prog_tag: 990e1f8152f7e54f
prog_id: 59
target_name: task
Signed-off-by: Yonghong Song <yhs@fb.com>
---
include/linux/bpf.h | 6 ++++
include/uapi/linux/bpf.h | 7 ++++
kernel/bpf/bpf_iter.c | 58 ++++++++++++++++++++++++++++++++++
tools/include/uapi/linux/bpf.h | 7 ++++
4 files changed, 78 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index a9b7185a6b37..529e9b183eeb 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1218,12 +1218,18 @@ typedef int (*bpf_iter_attach_target_t)(struct bpf_prog *prog,
union bpf_iter_link_info *linfo,
struct bpf_iter_aux_info *aux);
typedef void (*bpf_iter_detach_target_t)(struct bpf_iter_aux_info *aux);
+typedef void (*bpf_iter_show_fdinfo_t) (const struct bpf_iter_aux_info *aux,
+ struct seq_file *seq);
+typedef int (*bpf_iter_fill_link_info_t)(const struct bpf_iter_aux_info *aux,
+ struct bpf_link_info *info);
#define BPF_ITER_CTX_ARG_MAX 2
struct bpf_iter_reg {
const char *target;
bpf_iter_attach_target_t attach_target;
bpf_iter_detach_target_t detach_target;
+ bpf_iter_show_fdinfo_t show_fdinfo;
+ bpf_iter_fill_link_info_t fill_link_info;
u32 ctx_arg_info_size;
struct bpf_ctx_arg_aux ctx_arg_info[BPF_ITER_CTX_ARG_MAX];
const struct bpf_iter_seq_info *seq_info;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 0480f893facd..a1bbaff7a0af 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4071,6 +4071,13 @@ struct bpf_link_info {
__u64 cgroup_id;
__u32 attach_type;
} cgroup;
+ struct {
+ __aligned_u64 target_name; /* in/out: target_name buffer ptr */
+ __u32 target_name_len; /* in/out: target_name buffer len */
+ union {
+ __u32 map_id;
+ } map;
+ } iter;
struct {
__u32 netns_ino;
__u32 attach_type;
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index b6715964b685..aeec7e174188 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -377,10 +377,68 @@ static int bpf_iter_link_replace(struct bpf_link *link,
return ret;
}
+static void bpf_iter_link_show_fdinfo(const struct bpf_link *link,
+ struct seq_file *seq)
+{
+ struct bpf_iter_link *iter_link =
+ container_of(link, struct bpf_iter_link, link);
+ bpf_iter_show_fdinfo_t show_fdinfo;
+
+ seq_printf(seq,
+ "target_name:\t%s\n",
+ iter_link->tinfo->reg_info->target);
+
+ show_fdinfo = iter_link->tinfo->reg_info->show_fdinfo;
+ if (show_fdinfo)
+ show_fdinfo(&iter_link->aux, seq);
+}
+
+static int bpf_iter_link_fill_link_info(const struct bpf_link *link,
+ struct bpf_link_info *info)
+{
+ struct bpf_iter_link *iter_link =
+ container_of(link, struct bpf_iter_link, link);
+ char __user *ubuf = u64_to_user_ptr(info->iter.target_name);
+ bpf_iter_fill_link_info_t fill_link_info;
+ u32 ulen = info->iter.target_name_len;
+ const char *target_name;
+ u32 target_len;
+
+ if (!ulen ^ !ubuf)
+ return -EINVAL;
+
+ target_name = iter_link->tinfo->reg_info->target;
+ target_len = strlen(target_name);
+ info->iter.target_name_len = target_len + 1;
+
+ if (ubuf) {
+ if (ulen >= target_len + 1) {
+ if (copy_to_user(ubuf, target_name, target_len + 1))
+ return -EFAULT;
+ } else {
+ char zero = '\0';
+
+ if (copy_to_user(ubuf, target_name, ulen - 1))
+ return -EFAULT;
+ if (put_user(zero, ubuf + ulen - 1))
+ return -EFAULT;
+ return -ENOSPC;
+ }
+ }
+
+ fill_link_info = iter_link->tinfo->reg_info->fill_link_info;
+ if (fill_link_info)
+ return fill_link_info(&iter_link->aux, info);
+
+ return 0;
+}
+
static const struct bpf_link_ops bpf_iter_link_lops = {
.release = bpf_iter_link_release,
.dealloc = bpf_iter_link_dealloc,
.update_prog = bpf_iter_link_replace,
+ .show_fdinfo = bpf_iter_link_show_fdinfo,
+ .fill_link_info = bpf_iter_link_fill_link_info,
};
bool bpf_link_is_iter(struct bpf_link *link)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 0480f893facd..a1bbaff7a0af 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -4071,6 +4071,13 @@ struct bpf_link_info {
__u64 cgroup_id;
__u32 attach_type;
} cgroup;
+ struct {
+ __aligned_u64 target_name; /* in/out: target_name buffer ptr */
+ __u32 target_name_len; /* in/out: target_name buffer len */
+ union {
+ __u32 map_id;
+ } map;
+ } iter;
struct {
__u32 netns_ino;
__u32 attach_type;
--
2.24.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH bpf-next v4 2/3] bpf: implement link_query callbacks in map element iterators
2020-08-21 18:44 [PATCH bpf-next v4 0/3] bpf: implement link_query for bpf iterators Yonghong Song
2020-08-21 18:44 ` [PATCH bpf-next v4 1/3] " Yonghong Song
@ 2020-08-21 18:44 ` Yonghong Song
2020-08-21 18:44 ` [PATCH bpf-next v4 3/3] bpftool: implement link_query for bpf iterators Yonghong Song
2020-08-21 19:04 ` [PATCH bpf-next v4 0/3] bpf: " Andrii Nakryiko
3 siblings, 0 replies; 6+ messages in thread
From: Yonghong Song @ 2020-08-21 18:44 UTC (permalink / raw)
To: bpf, netdev; +Cc: Alexei Starovoitov, Daniel Borkmann, kernel-team
For bpf_map_elem and bpf_sk_local_storage bpf iterators,
additional map_id should be shown for fdinfo and
userspace query. For example, the following is for
a bpf_map_elem iterator.
$ cat /proc/1753/fdinfo/9
pos: 0
flags: 02000000
mnt_id: 14
link_type: iter
link_id: 34
prog_tag: 104be6d3fe45e6aa
prog_id: 173
target_name: bpf_map_elem
map_id: 127
Signed-off-by: Yonghong Song <yhs@fb.com>
---
include/linux/bpf.h | 4 ++++
kernel/bpf/map_iter.c | 15 +++++++++++++++
net/core/bpf_sk_storage.c | 2 ++
3 files changed, 21 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 529e9b183eeb..30c144af894a 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1256,6 +1256,10 @@ int bpf_iter_new_fd(struct bpf_link *link);
bool bpf_link_is_iter(struct bpf_link *link);
struct bpf_prog *bpf_iter_get_info(struct bpf_iter_meta *meta, bool in_stop);
int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx);
+void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
+ struct seq_file *seq);
+int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
+ struct bpf_link_info *info);
int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
index af86048e5afd..6a9542af4212 100644
--- a/kernel/bpf/map_iter.c
+++ b/kernel/bpf/map_iter.c
@@ -149,6 +149,19 @@ static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
bpf_map_put_with_uref(aux->map);
}
+void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
+ struct seq_file *seq)
+{
+ seq_printf(seq, "map_id:\t%u\n", aux->map->id);
+}
+
+int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
+ struct bpf_link_info *info)
+{
+ info->iter.map.map_id = aux->map->id;
+ return 0;
+}
+
DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta,
struct bpf_map *map, void *key, void *value)
@@ -156,6 +169,8 @@ static const struct bpf_iter_reg bpf_map_elem_reg_info = {
.target = "bpf_map_elem",
.attach_target = bpf_iter_attach_map,
.detach_target = bpf_iter_detach_map,
+ .show_fdinfo = bpf_iter_map_show_fdinfo,
+ .fill_link_info = bpf_iter_map_fill_link_info,
.ctx_arg_info_size = 2,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_map_elem, key),
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index b988f48153a4..281200dc0a01 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -1437,6 +1437,8 @@ static struct bpf_iter_reg bpf_sk_storage_map_reg_info = {
.target = "bpf_sk_storage_map",
.attach_target = bpf_iter_attach_map,
.detach_target = bpf_iter_detach_map,
+ .show_fdinfo = bpf_iter_map_show_fdinfo,
+ .fill_link_info = bpf_iter_map_fill_link_info,
.ctx_arg_info_size = 2,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_sk_storage_map, sk),
--
2.24.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH bpf-next v4 3/3] bpftool: implement link_query for bpf iterators
2020-08-21 18:44 [PATCH bpf-next v4 0/3] bpf: implement link_query for bpf iterators Yonghong Song
2020-08-21 18:44 ` [PATCH bpf-next v4 1/3] " Yonghong Song
2020-08-21 18:44 ` [PATCH bpf-next v4 2/3] bpf: implement link_query callbacks in map element iterators Yonghong Song
@ 2020-08-21 18:44 ` Yonghong Song
2020-08-21 19:04 ` [PATCH bpf-next v4 0/3] bpf: " Andrii Nakryiko
3 siblings, 0 replies; 6+ messages in thread
From: Yonghong Song @ 2020-08-21 18:44 UTC (permalink / raw)
To: bpf, netdev
Cc: Alexei Starovoitov, Daniel Borkmann, kernel-team, Andrii Nakryiko
The link query for bpf iterators is implemented.
Besides being shown to the user what bpf iterator
the link represents, the target_name is also used
to filter out what additional information should be
printed out, e.g., whether map_id should be shown or not.
The following is an example of bpf_iter link dump,
plain output or pretty output.
$ bpftool link show
11: iter prog 59 target_name task
pids test_progs(1749)
34: iter prog 173 target_name bpf_map_elem map_id 127
pids test_progs_1(1753)
$ bpftool -p link show
[{
"id": 11,
"type": "iter",
"prog_id": 59,
"target_name": "task",
"pids": [{
"pid": 1749,
"comm": "test_progs"
}
]
},{
"id": 34,
"type": "iter",
"prog_id": 173,
"target_name": "bpf_map_elem",
"map_id": 127,
"pids": [{
"pid": 1753,
"comm": "test_progs_1"
}
]
}
]
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
tools/bpf/bpftool/link.c | 44 +++++++++++++++++++++++++++++++++++++---
1 file changed, 41 insertions(+), 3 deletions(-)
diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
index a89f09e3c848..e77e1525d20a 100644
--- a/tools/bpf/bpftool/link.c
+++ b/tools/bpf/bpftool/link.c
@@ -77,6 +77,22 @@ static void show_link_attach_type_json(__u32 attach_type, json_writer_t *wtr)
jsonw_uint_field(wtr, "attach_type", attach_type);
}
+static bool is_iter_map_target(const char *target_name)
+{
+ return strcmp(target_name, "bpf_map_elem") == 0 ||
+ strcmp(target_name, "bpf_sk_storage_map") == 0;
+}
+
+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);
+
+ jsonw_string_field(wtr, "target_name", target_name);
+
+ if (is_iter_map_target(target_name))
+ jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
+}
+
static int get_prog_info(int prog_id, struct bpf_prog_info *info)
{
__u32 len = sizeof(*info);
@@ -128,6 +144,9 @@ static int show_link_close_json(int fd, struct bpf_link_info *info)
info->cgroup.cgroup_id);
show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
break;
+ case BPF_LINK_TYPE_ITER:
+ show_iter_json(info, json_wtr);
+ break;
case BPF_LINK_TYPE_NETNS:
jsonw_uint_field(json_wtr, "netns_ino",
info->netns.netns_ino);
@@ -175,6 +194,16 @@ static void show_link_attach_type_plain(__u32 attach_type)
printf("attach_type %u ", attach_type);
}
+static void show_iter_plain(struct bpf_link_info *info)
+{
+ const char *target_name = u64_to_ptr(info->iter.target_name);
+
+ printf("target_name %s ", target_name);
+
+ if (is_iter_map_target(target_name))
+ printf("map_id %u ", info->iter.map.map_id);
+}
+
static int show_link_close_plain(int fd, struct bpf_link_info *info)
{
struct bpf_prog_info prog_info;
@@ -204,6 +233,9 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info)
printf("\n\tcgroup_id %zu ", (size_t)info->cgroup.cgroup_id);
show_link_attach_type_plain(info->cgroup.attach_type);
break;
+ case BPF_LINK_TYPE_ITER:
+ show_iter_plain(info);
+ break;
case BPF_LINK_TYPE_NETNS:
printf("\n\tnetns_ino %u ", info->netns.netns_ino);
show_link_attach_type_plain(info->netns.attach_type);
@@ -231,7 +263,7 @@ static int do_show_link(int fd)
{
struct bpf_link_info info;
__u32 len = sizeof(info);
- char raw_tp_name[256];
+ char buf[256];
int err;
memset(&info, 0, sizeof(info));
@@ -245,8 +277,14 @@ static int do_show_link(int fd)
}
if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
!info.raw_tracepoint.tp_name) {
- info.raw_tracepoint.tp_name = (unsigned long)&raw_tp_name;
- info.raw_tracepoint.tp_name_len = sizeof(raw_tp_name);
+ info.raw_tracepoint.tp_name = (unsigned long)&buf;
+ info.raw_tracepoint.tp_name_len = sizeof(buf);
+ goto again;
+ }
+ if (info.type == BPF_LINK_TYPE_ITER &&
+ !info.iter.target_name) {
+ info.iter.target_name = (unsigned long)&buf;
+ info.iter.target_name_len = sizeof(buf);
goto again;
}
--
2.24.1
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH bpf-next v4 0/3] bpf: implement link_query for bpf iterators
2020-08-21 18:44 [PATCH bpf-next v4 0/3] bpf: implement link_query for bpf iterators Yonghong Song
` (2 preceding siblings ...)
2020-08-21 18:44 ` [PATCH bpf-next v4 3/3] bpftool: implement link_query for bpf iterators Yonghong Song
@ 2020-08-21 19:04 ` Andrii Nakryiko
2020-08-21 21:17 ` Alexei Starovoitov
3 siblings, 1 reply; 6+ messages in thread
From: Andrii Nakryiko @ 2020-08-21 19:04 UTC (permalink / raw)
To: Yonghong Song
Cc: bpf, Networking, Alexei Starovoitov, Daniel Borkmann, Kernel Team
On Fri, Aug 21, 2020 at 11:44 AM Yonghong Song <yhs@fb.com> wrote:
>
> "link" has been an important concept for bpf ecosystem to connect
> bpf program with other properties. Currently, the information related
> information can be queried from userspace through bpf command
> BPF_LINK_GET_NEXT_ID, BPF_LINK_GET_FD_BY_ID and BPF_OBJ_GET_INFO_BY_FD.
> The information is also available by "cating" /proc/<pid>/fdinfo/<link_fd>.
> Raw_tracepoint, tracing, cgroup, netns and xdp links are already
> supported in the kernel and bpftool.
>
> This patch added support for bpf iterator. Patch #1 added generic support
> for link querying interface. Patch #2 implemented callback functions
> for map element bpf iterators. Patch #3 added bpftool support.
>
> Changelogs:
> v3 -> v4:
> . return target specific link_info even if target_name buffer
> is empty. (Andrii)
> v2 -> v3:
> . remove extra '\t' when fdinfo prints map_id to make parsing
> consistent. (Andrii)
> v1 -> v2:
> . fix checkpatch.pl warnings. (Jakub)
>
> Yonghong Song (3):
> bpf: implement link_query for bpf iterators
> bpf: implement link_query callbacks in map element iterators
> bpftool: implement link_query for bpf iterators
>
> include/linux/bpf.h | 10 ++++++
> include/uapi/linux/bpf.h | 7 ++++
> kernel/bpf/bpf_iter.c | 58 ++++++++++++++++++++++++++++++++++
> kernel/bpf/map_iter.c | 15 +++++++++
> net/core/bpf_sk_storage.c | 2 ++
> tools/bpf/bpftool/link.c | 44 ++++++++++++++++++++++++--
> tools/include/uapi/linux/bpf.h | 7 ++++
> 7 files changed, 140 insertions(+), 3 deletions(-)
>
> --
> 2.24.1
>
LGTM, thanks.
Acked-by: Andrii Nakryiko <andriin@fb.com>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH bpf-next v4 0/3] bpf: implement link_query for bpf iterators
2020-08-21 19:04 ` [PATCH bpf-next v4 0/3] bpf: " Andrii Nakryiko
@ 2020-08-21 21:17 ` Alexei Starovoitov
0 siblings, 0 replies; 6+ messages in thread
From: Alexei Starovoitov @ 2020-08-21 21:17 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: Yonghong Song, bpf, Networking, Alexei Starovoitov,
Daniel Borkmann, Kernel Team
On Fri, Aug 21, 2020 at 12:04 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Fri, Aug 21, 2020 at 11:44 AM Yonghong Song <yhs@fb.com> wrote:
> >
> > "link" has been an important concept for bpf ecosystem to connect
> > bpf program with other properties. Currently, the information related
> > information can be queried from userspace through bpf command
> > BPF_LINK_GET_NEXT_ID, BPF_LINK_GET_FD_BY_ID and BPF_OBJ_GET_INFO_BY_FD.
> > The information is also available by "cating" /proc/<pid>/fdinfo/<link_fd>.
> > Raw_tracepoint, tracing, cgroup, netns and xdp links are already
> > supported in the kernel and bpftool.
> >
> > This patch added support for bpf iterator. Patch #1 added generic support
> > for link querying interface. Patch #2 implemented callback functions
> > for map element bpf iterators. Patch #3 added bpftool support.
> >
> > Changelogs:
> > v3 -> v4:
> > . return target specific link_info even if target_name buffer
> > is empty. (Andrii)
> > v2 -> v3:
> > . remove extra '\t' when fdinfo prints map_id to make parsing
> > consistent. (Andrii)
> > v1 -> v2:
> > . fix checkpatch.pl warnings. (Jakub)
> >
> > Yonghong Song (3):
> > bpf: implement link_query for bpf iterators
> > bpf: implement link_query callbacks in map element iterators
> > bpftool: implement link_query for bpf iterators
> >
> > include/linux/bpf.h | 10 ++++++
> > include/uapi/linux/bpf.h | 7 ++++
> > kernel/bpf/bpf_iter.c | 58 ++++++++++++++++++++++++++++++++++
> > kernel/bpf/map_iter.c | 15 +++++++++
> > net/core/bpf_sk_storage.c | 2 ++
> > tools/bpf/bpftool/link.c | 44 ++++++++++++++++++++++++--
> > tools/include/uapi/linux/bpf.h | 7 ++++
> > 7 files changed, 140 insertions(+), 3 deletions(-)
> >
> > --
> > 2.24.1
> >
>
> LGTM, thanks.
>
> Acked-by: Andrii Nakryiko <andriin@fb.com>
Applied. Thanks
^ permalink raw reply [flat|nested] 6+ messages in thread