bpftool: make key and value optional in update command

Bpftool expects both key and value for 'update' operations. For some
map types, key should not be specified. Support updating those map types.

Before:
bpftool map create /sys/fs/bpf/q type queue value 4 entries 10 name q
bpftool map update pinned /sys/fs/bpf/q value 0 1 2 3
Error: did not find key

After:
bpftool map create /sys/fs/bpf/q type queue value 4 entries 10 name q
bpftool map update pinned /sys/fs/bpf/q value 0 1 2 3

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Stanislav Fomichev 2019-01-16 11:09:59 -08:00 committed by Daniel Borkmann
parent e13279e211
commit 7d7209cb9a
2 changed files with 31 additions and 9 deletions

View file

@ -25,7 +25,7 @@ MAP COMMANDS
| **bpftool** **map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \
| **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
| **bpftool** **map dump** *MAP*
| **bpftool** **map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*]
| **bpftool** **map update** *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]
| **bpftool** **map lookup** *MAP* **key** *DATA*
| **bpftool** **map getnext** *MAP* [**key** *DATA*]
| **bpftool** **map delete** *MAP* **key** *DATA*
@ -62,7 +62,7 @@ DESCRIPTION
**bpftool map dump** *MAP*
Dump all entries in a given *MAP*.
**bpftool map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*]
**bpftool map update** *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]
Update map entry for a given *KEY*.
*UPDATE_FLAGS* can be one of: **any** update existing entry

View file

@ -779,6 +779,32 @@ static int do_dump(int argc, char **argv)
return err;
}
static int alloc_key_value(struct bpf_map_info *info, void **key, void **value)
{
*key = NULL;
*value = NULL;
if (info->key_size) {
*key = malloc(info->key_size);
if (!*key) {
p_err("key mem alloc failed");
return -1;
}
}
if (info->value_size) {
*value = alloc_value(info);
if (!*value) {
p_err("value mem alloc failed");
free(*key);
*key = NULL;
return -1;
}
}
return 0;
}
static int do_update(int argc, char **argv)
{
struct bpf_map_info info = {};
@ -795,13 +821,9 @@ static int do_update(int argc, char **argv)
if (fd < 0)
return -1;
key = malloc(info.key_size);
value = alloc_value(&info);
if (!key || !value) {
p_err("mem alloc failed");
err = -1;
err = alloc_key_value(&info, &key, &value);
if (err)
goto exit_free;
}
err = parse_elem(argv, &info, key, value, info.key_size,
info.value_size, &flags, &value_fd);
@ -1135,7 +1157,7 @@ static int do_help(int argc, char **argv)
" entries MAX_ENTRIES name NAME [flags FLAGS] \\\n"
" [dev NAME]\n"
" %s %s dump MAP\n"
" %s %s update MAP key DATA value VALUE [UPDATE_FLAGS]\n"
" %s %s update MAP [key DATA] [value VALUE] [UPDATE_FLAGS]\n"
" %s %s lookup MAP key DATA\n"
" %s %s getnext MAP [key DATA]\n"
" %s %s delete MAP key DATA\n"