From: Jakub Sitnicki <jakub@cloudflare.com>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, kernel-team@cloudflare.com,
Eric Dumazet <edumazet@google.com>,
John Fastabend <john.fastabend@gmail.com>,
Lorenz Bauer <lmb@cloudflare.com>,
Martin KaFai Lau <kafai@fb.com>
Subject: [PATCH bpf-next v2 09/11] bpf: Allow selecting reuseport socket from a SOCKMAP
Date: Fri, 10 Jan 2020 11:50:25 +0100 [thread overview]
Message-ID: <20200110105027.257877-10-jakub@cloudflare.com> (raw)
In-Reply-To: <20200110105027.257877-1-jakub@cloudflare.com>
SOCKMAP now supports storing references to listening sockets. Nothing keeps
us from using it as an array of sockets to select from in SK_REUSEPORT
programs.
Whitelist the map type with the BPF helper for selecting socket.
The restriction that the socket has to be a member of a reuseport group
still applies. Socket from a SOCKMAP that does not have sk_reuseport_cb set
is not a valid target and we signal it with -EINVAL.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
kernel/bpf/verifier.c | 6 ++++--
net/core/filter.c | 15 ++++++++++-----
2 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index f5af759a8a5f..0ee5f1594b5c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3697,7 +3697,8 @@ 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:
@@ -3778,7 +3779,8 @@ 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)
goto error;
break;
case BPF_FUNC_map_peek_elem:
diff --git a/net/core/filter.c b/net/core/filter.c
index a702761ef369..c79c62a54167 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -8677,6 +8677,7 @@ struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
BPF_CALL_4(sk_select_reuseport, struct sk_reuseport_kern *, reuse_kern,
struct bpf_map *, map, void *, key, u32, flags)
{
+ bool is_sockarray = map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY;
struct sock_reuseport *reuse;
struct sock *selected_sk;
@@ -8685,12 +8686,16 @@ BPF_CALL_4(sk_select_reuseport, struct sk_reuseport_kern *, reuse_kern,
return -ENOENT;
reuse = rcu_dereference(selected_sk->sk_reuseport_cb);
- if (!reuse)
- /* selected_sk is unhashed (e.g. by close()) after the
- * above map_lookup_elem(). Treat selected_sk has already
- * been removed from the map.
+ if (!reuse) {
+ /* reuseport_array has only sk with non NULL sk_reuseport_cb.
+ * The only (!reuse) case here is - the sk has already been
+ * unhashed (e.g. by close()), so treat it as -ENOENT.
+ *
+ * Other maps (e.g. sock_map) do not provide this guarantee and
+ * the sk may never be in the reuseport group to begin with.
*/
- return -ENOENT;
+ return is_sockarray ? -ENOENT : -EINVAL;
+ }
if (unlikely(reuse->reuseport_id != reuse_kern->reuseport_id)) {
struct sock *sk;
--
2.24.1
next prev parent reply other threads:[~2020-01-10 10:50 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-10 10:50 [PATCH bpf-next v2 00/11] Extend SOCKMAP to store listening sockets Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 01/11] bpf, sk_msg: Don't reset saved sock proto on restore Jakub Sitnicki
2020-01-11 22:50 ` John Fastabend
2020-01-10 10:50 ` [PATCH bpf-next v2 02/11] net, sk_msg: Annotate lockless access to sk_prot on clone Jakub Sitnicki
2020-01-11 23:14 ` John Fastabend
2020-01-13 15:09 ` Jakub Sitnicki
2020-01-14 3:14 ` John Fastabend
2020-01-20 17:00 ` John Fastabend
2020-01-20 18:11 ` Jakub Sitnicki
2020-01-21 12:42 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 03/11] net, sk_msg: Clear sk_user_data pointer on clone if tagged Jakub Sitnicki
2020-01-11 23:38 ` John Fastabend
2020-01-12 12:55 ` kbuild test robot
2020-01-13 20:15 ` Martin Lau
2020-01-14 16:04 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 04/11] tcp_bpf: Don't let child socket inherit parent protocol ops on copy Jakub Sitnicki
2020-01-11 2:42 ` kbuild test robot
2020-01-11 3:02 ` kbuild test robot
2020-01-11 23:48 ` John Fastabend
2020-01-13 22:31 ` Jakub Sitnicki
2020-01-13 22:23 ` Martin Lau
2020-01-13 22:42 ` Jakub Sitnicki
2020-01-13 23:23 ` Martin Lau
2020-01-10 10:50 ` [PATCH bpf-next v2 05/11] bpf, sockmap: Allow inserting listening TCP sockets into sockmap Jakub Sitnicki
2020-01-11 23:59 ` John Fastabend
2020-01-13 15:48 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 06/11] bpf, sockmap: Don't set up sockmap progs for listening sockets Jakub Sitnicki
2020-01-12 0:51 ` John Fastabend
2020-01-12 1:07 ` John Fastabend
2020-01-13 17:59 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 07/11] bpf, sockmap: Return socket cookie on lookup from syscall Jakub Sitnicki
2020-01-12 0:56 ` John Fastabend
2020-01-13 23:12 ` Martin Lau
2020-01-14 3:16 ` John Fastabend
2020-01-14 15:48 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 08/11] bpf, sockmap: Let all kernel-land lookup values in SOCKMAP Jakub Sitnicki
2020-01-10 10:50 ` Jakub Sitnicki [this message]
2020-01-12 1:00 ` [PATCH bpf-next v2 09/11] bpf: Allow selecting reuseport socket from a SOCKMAP John Fastabend
2020-01-13 23:45 ` Martin Lau
2020-01-15 12:41 ` Jakub Sitnicki
2020-01-13 23:51 ` Martin Lau
2020-01-15 12:57 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 10/11] selftests/bpf: Extend SK_REUSEPORT tests to cover SOCKMAP Jakub Sitnicki
2020-01-12 1:01 ` John Fastabend
2020-01-10 10:50 ` [PATCH bpf-next v2 11/11] selftests/bpf: Tests for SOCKMAP holding listening sockets Jakub Sitnicki
2020-01-12 1:06 ` John Fastabend
2020-01-13 15:58 ` Jakub Sitnicki
2020-01-11 0:18 ` [PATCH bpf-next v2 00/11] Extend SOCKMAP to store " Alexei Starovoitov
2020-01-11 22:47 ` John Fastabend
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