xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bpf: Allow selecting reuseport socket from a SOCKMAP/SOCKHASH

Browse Source 
SOCKMAP & SOCKHASH now support storing references to listening
sockets. Nothing keeps us from using these map types a collection of
sockets to select from in BPF reuseport programs. Whitelist the map types
with the bpf_sk_select_reuseport helper.

The restriction that the socket has to be a member of a reuseport group
still applies. Sockets in SOCKMAP/SOCKHASH that don't have sk_reuseport_cb
set are not a valid target and we signal it with -EINVAL.

The main benefit from this change is that, in contrast to
REUSEPORT_SOCKARRAY, SOCK{MAP,HASH} don't impose a restriction that a
listening socket can be just one BPF map at the same time.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200218171023.844439-9-jakub@cloudflare.com
This commit is contained in:
Jakub Sitnicki
2020-02-18 17:10:20 +00:00
committed by Daniel Borkmann
parent 1d59f3bcee
commit 9fed9000c5
2 changed files with 17 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
kernel/bpf/verifier.c
View File

@@ -3693,14 +3693,16 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
if (func_id != BPF_FUNC_sk_redirect_map &&
func_id != BPF_FUNC_sock_map_update &&
func_id != BPF_FUNC_map_delete_elem &&
func_id != BPF_FUNC_msg_redirect_map)
func_id != BPF_FUNC_msg_redirect_map &&
func_id != BPF_FUNC_sk_select_reuseport)
goto error;
break;
case BPF_MAP_TYPE_SOCKHASH:
if (func_id != BPF_FUNC_sk_redirect_hash &&
func_id != BPF_FUNC_sock_hash_update &&
func_id != BPF_FUNC_map_delete_elem &&
func_id != BPF_FUNC_msg_redirect_hash)
func_id != BPF_FUNC_msg_redirect_hash &&
func_id != BPF_FUNC_sk_select_reuseport)
goto error;
break;
case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
@@ -3774,7 +3776,9 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
goto error;
break;
case BPF_FUNC_sk_select_reuseport:
if (map->map_type != BPF_MAP_TYPE_REUSEPORT_SOCKARRAY)
if (map->map_type != BPF_MAP_TYPE_REUSEPORT_SOCKARRAY &&
map->map_type != BPF_MAP_TYPE_SOCKMAP &&
map->map_type != BPF_MAP_TYPE_SOCKHASH)
goto error;
break;
case BPF_FUNC_map_peek_elem: