@@ -33,7 +33,9 @@ MAP COMMANDS
| **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*]
| **bpftool** **map peek** *MAP*
| **bpftool** **map push** *MAP* **value** *VALUE*
+| **bpftool** **map pop** *MAP*
| **bpftool** **map enqueue** *MAP* **value** *VALUE*
+| **bpftool** **map dequeue** *MAP*
| **bpftool** **map help**
|
| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
@@ -116,9 +118,15 @@ DESCRIPTION
**bpftool map push** *MAP* **value** *VALUE*
Push **value** onto the stack.
+ **bpftool map pop** *MAP*
+ Pop and print **value** from the stack.
+
**bpftool map enqueue** *MAP* **value** *VALUE*
Enqueue **value** into the queue.
+ **bpftool map dequeue** *MAP*
+ Dequeue and print **value** from the queue.
+
**bpftool map help**
Print short help message.
@@ -857,12 +857,51 @@ static int do_update(int argc, char **argv)
return err;
}
+static void print_key_value(struct bpf_map_info *info, void *key,
+ void *value)
+{
+ json_writer_t *btf_wtr;
+ struct btf *btf = NULL;
+ int err;
+
+ err = btf__get_from_id(info->btf_id, &btf);
+ if (err) {
+ p_err("failed to get btf");
+ return;
+ }
+
+ if (json_output) {
+ print_entry_json(info, key, value, btf);
+ } else if (btf) {
+ /* if here json_wtr wouldn't have been initialised,
+ * so let's create separate writer for btf
+ */
+ btf_wtr = get_btf_writer();
+ if (!btf_wtr) {
+ p_info("failed to create json writer for btf. falling back to plain output");
+ btf__free(btf);
+ btf = NULL;
+ print_entry_plain(info, key, value);
+ } else {
+ struct btf_dumper d = {
+ .btf = btf,
+ .jw = btf_wtr,
+ .is_plain_text = true,
+ };
+
+ do_dump_btf(&d, info, key, value);
+ jsonw_destroy(&btf_wtr);
+ }
+ } else {
+ print_entry_plain(info, key, value);
+ }
+ btf__free(btf);
+}
+
static int do_lookup(int argc, char **argv)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
- json_writer_t *btf_wtr;
- struct btf *btf = NULL;
void *key, *value;
int err;
int fd;
@@ -900,43 +939,12 @@ static int do_lookup(int argc, char **argv)
}
/* here means bpf_map_lookup_elem() succeeded */
- err = btf__get_from_id(info.btf_id, &btf);
- if (err) {
- p_err("failed to get btf");
- goto exit_free;
- }
-
- if (json_output) {
- print_entry_json(&info, key, value, btf);
- } else if (btf) {
- /* if here json_wtr wouldn't have been initialised,
- * so let's create separate writer for btf
- */
- btf_wtr = get_btf_writer();
- if (!btf_wtr) {
- p_info("failed to create json writer for btf. falling back to plain output");
- btf__free(btf);
- btf = NULL;
- print_entry_plain(&info, key, value);
- } else {
- struct btf_dumper d = {
- .btf = btf,
- .jw = btf_wtr,
- .is_plain_text = true,
- };
-
- do_dump_btf(&d, &info, key, value);
- jsonw_destroy(&btf_wtr);
- }
- } else {
- print_entry_plain(&info, key, value);
- }
+ print_key_value(&info, key, value);
exit_free:
free(key);
free(value);
close(fd);
- btf__free(btf);
return err;
}
@@ -1149,6 +1157,49 @@ static int do_create(int argc, char **argv)
return 0;
}
+static int do_pop_dequeue(int argc, char **argv)
+{
+ struct bpf_map_info info = {};
+ __u32 len = sizeof(info);
+ void *key, *value;
+ int err;
+ int fd;
+
+ if (argc < 2)
+ usage();
+
+ fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
+ if (fd < 0)
+ return -1;
+
+ err = alloc_key_value(&info, &key, &value);
+ if (err)
+ goto exit_free;
+
+ err = bpf_map_lookup_and_delete_elem(fd, key, value);
+ if (err) {
+ if (errno == ENOENT) {
+ if (json_output)
+ jsonw_null(json_wtr);
+ else
+ printf("Error: empty map\n");
+ } else {
+ p_err("pop failed: %s", strerror(errno));
+ }
+
+ goto exit_free;
+ }
+
+ print_key_value(&info, key, value);
+
+exit_free:
+ free(key);
+ free(value);
+ close(fd);
+
+ return err;
+}
+
static int do_help(int argc, char **argv)
{
if (json_output) {
@@ -1170,7 +1221,9 @@ static int do_help(int argc, char **argv)
" %s %s event_pipe MAP [cpu N index M]\n"
" %s %s peek MAP\n"
" %s %s push MAP value VALUE\n"
+ " %s %s pop MAP\n"
" %s %s enqueue MAP value VALUE\n"
+ " %s %s dequeue MAP\n"
" %s %s help\n"
"\n"
" " HELP_SPEC_MAP "\n"
@@ -1189,7 +1242,7 @@ static int do_help(int argc, char **argv)
bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
- bin_name, argv[-2]);
+ bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
return 0;
}
@@ -1209,6 +1262,8 @@ static const struct cmd cmds[] = {
{ "peek", do_lookup },
{ "push", do_update },
{ "enqueue", do_update },
+ { "pop", do_pop_dequeue },
+ { "dequeue", do_pop_dequeue },
{ 0 }
};
This is intended to be used with queues and stacks, it pops and prints the last element via bpf_map_lookup_and_delete_elem. Example: bpftool map create /sys/fs/bpf/q type queue value 4 entries 10 name q bpftool map push pinned /sys/fs/bpf/q value 0 1 2 3 bpftool map pop pinned /sys/fs/bpf/q value: 00 01 02 03 bpftool map pop pinned /sys/fs/bpf/q Error: empty map bpftool map create /sys/fs/bpf/s type stack value 4 entries 10 name s bpftool map enqueue pinned /sys/fs/bpf/s value 0 1 2 3 bpftool map dequeue pinned /sys/fs/bpf/s value: 00 01 02 03 bpftool map dequeue pinned /sys/fs/bpf/s Error: empty map Signed-off-by: Stanislav Fomichev <sdf@google.com> --- .../bpf/bpftool/Documentation/bpftool-map.rst | 8 ++ tools/bpf/bpftool/map.c | 125 +++++++++++++----- 2 files changed, 98 insertions(+), 35 deletions(-)