[PATCH mptcp-next v3 0/5] Squash to "Add mptcp_subflow bpf_iter support"

[PATCH mptcp-next v3 0/5] Squash to "Add mptcp_subflow bpf_iter support"

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

v3:
 - check sock_owned_by_user_nocheck(sk)/spin_is_locked(&sk->sk_lock.slock),
   instead of lockdep_sock_is_held(sk).
 - add "sizeof" and "alignof" checks.
 - drop bpf_mptcp_sk() and bpf_mptcp_subflow_tcp_sock() definitions. Use
   bpf_skc_to_mptcp_sock() and mptcp_subflow_tcp_sock() in mptcp_subflow
   bpf_iter selftests instead.

v2:
 - add CONFIG_LOCKDEP check in patch 2 to fix the build error reported
   by CI.

Address Martin's comments in v1.

Geliang Tang (5):
  mptcp: update bpf_mptcp_sock_from_subflow
  bpf: Allow use of skc_to_mptcp_sock in cg_sockopt
  Squash to "bpf: Register mptcp common kfunc set"
  Squash to "bpf: Add mptcp_subflow bpf_iter"
  Squash to "selftests/bpf: Add mptcp_subflow bpf_iter subtest"

 include/net/mptcp.h                           |  4 +--
 kernel/bpf/cgroup.c                           |  2 ++
 net/core/filter.c                             |  2 +-
 net/mptcp/bpf.c                               | 34 +++++++++----------
 tools/testing/selftests/bpf/progs/mptcp_bpf.h |  1 -
 .../selftests/bpf/progs/mptcp_bpf_iters.c     | 11 +++---
 6 files changed, 27 insertions(+), 27 deletions(-)

-- 
2.45.2

[PATCH mptcp-next v3 1/5] mptcp: update bpf_mptcp_sock_from_subflow

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

The input parameter of bpf_mptcp_sock_from_subflow() is an msk subsocket
of type IPPROTO_TCP. This patch extends it to accept an IPPROTO_MPTCP
socket. With this change, the function name bpf_mptcp_sock_from_subflow
is no longer appropriate, and it is renamed to bpf_mptcp_sock_from_sock.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h | 4 ++--
 net/core/filter.c   | 2 +-
 net/mptcp/bpf.c     | 4 +++-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 814b5f2e3ed5..94d5976f7b8d 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -322,9 +322,9 @@ static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
 #endif
 
 #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
-struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
+struct mptcp_sock *bpf_mptcp_sock_from_sock(struct sock *sk);
 #else
-static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
+static inline struct mptcp_sock *bpf_mptcp_sock_from_sock(struct sock *sk) { return NULL; }
 #endif
 
 #if !IS_ENABLED(CONFIG_MPTCP)
diff --git a/net/core/filter.c b/net/core/filter.c
index fac245065b0a..9ac048f0c5dd 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -11836,7 +11836,7 @@ const struct bpf_func_proto bpf_skc_to_unix_sock_proto = {
 BPF_CALL_1(bpf_skc_to_mptcp_sock, struct sock *, sk)
 {
 	BTF_TYPE_EMIT(struct mptcp_sock);
-	return (unsigned long)bpf_mptcp_sock_from_subflow(sk);
+	return (unsigned long)bpf_mptcp_sock_from_sock(sk);
 }
 
 const struct bpf_func_proto bpf_skc_to_mptcp_sock_proto = {
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index e9db856972cb..a0f49af85d57 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -188,8 +188,10 @@ static struct bpf_struct_ops bpf_mptcp_sched_ops = {
 };
 #endif /* CONFIG_BPF_JIT */
 
-struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk)
+struct mptcp_sock *bpf_mptcp_sock_from_sock(struct sock *sk)
 {
+	if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_MPTCP)
+		return mptcp_sk(sk);
 	if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk))
 		return mptcp_sk(mptcp_subflow_ctx(sk)->conn);
 
-- 
2.45.2

[PATCH mptcp-next v3 2/5] bpf: Allow use of skc_to_mptcp_sock in cg_sockopt

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Currently, bpf_skc_to_mptcp_sock() helper is not allowed to be used
in cg_sockopt. This patch adds this permission.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 kernel/bpf/cgroup.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 46e5db65dbc8..1ca22e4842cf 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -2358,6 +2358,8 @@ cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 #ifdef CONFIG_INET
 	case BPF_FUNC_tcp_sock:
 		return &bpf_tcp_sock_proto;
+	case BPF_FUNC_skc_to_mptcp_sock:
+		return &bpf_skc_to_mptcp_sock_proto;
 #endif
 	case BPF_FUNC_perf_event_output:
 		return &bpf_event_output_data_proto;
-- 
2.45.2

[PATCH mptcp-next v3 3/5] Squash to "bpf: Register mptcp common kfunc set"

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Drop bpf_mptcp_sk() and bpf_mptcp_subflow_tcp_sock() definitions. Use
bpf_skc_to_mptcp_sock() and mptcp_subflow_tcp_sock() in mptcp_subflow
bpf_iter selftests instead.

Address Martin's comments in v1:

- add null-check for bpf_mptcp_subflow_ctx.
- add KF_RET_NULL flags for bpf_mptcp_subflow_ctx.
- register this kfunc set to BPF_PROG_TYPE_CGROUP_SOCKOPT only,
  not BPF_PROG_TYPE_UNSPEC.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/bpf.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index a0f49af85d57..f9ba0a46a9f1 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -218,21 +218,13 @@ struct bpf_iter_mptcp_subflow_kern {
 
 __bpf_kfunc_start_defs();
 
-__bpf_kfunc static struct mptcp_sock *bpf_mptcp_sk(struct sock *sk)
-{
-	return mptcp_sk(sk);
-}
-
 __bpf_kfunc static struct mptcp_subflow_context *
 bpf_mptcp_subflow_ctx(const struct sock *sk)
 {
-	return mptcp_subflow_ctx(sk);
-}
+	if (!sk)
+		return NULL;
 
-__bpf_kfunc static struct sock *
-bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
-{
-	return mptcp_subflow_tcp_sock(subflow);
+	return mptcp_subflow_ctx(sk);
 }
 
 __bpf_kfunc static int
@@ -301,9 +293,7 @@ __bpf_kfunc static bool bpf_mptcp_subflow_queues_empty(struct sock *sk)
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(bpf_mptcp_common_kfunc_ids)
-BTF_ID_FLAGS(func, bpf_mptcp_sk)
-BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx)
-BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock)
+BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx, KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_new, KF_ITER_NEW | KF_TRUSTED_ARGS)
 BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_next, KF_ITER_NEXT | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_destroy, KF_ITER_DESTROY)
@@ -337,7 +327,7 @@ static int __init bpf_mptcp_kfunc_init(void)
 	int ret;
 
 	ret = register_btf_fmodret_id_set(&bpf_mptcp_fmodret_set);
-	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC,
+	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SOCKOPT,
 					       &bpf_mptcp_common_kfunc_set);
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS,
 					       &bpf_mptcp_sched_kfunc_set);
-- 
2.45.2

[PATCH mptcp-next v3 4/5] Squash to "bpf: Add mptcp_subflow bpf_iter"

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Add "sizeof" and "alignof" checks.

Address Martin's comments in v1:

- bpf_iter_mptcp_subflow_new returns -EINVAL when msk socket lock isn't
  held.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/bpf.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index f9ba0a46a9f1..566c3a32ab73 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -232,12 +232,20 @@ bpf_iter_mptcp_subflow_new(struct bpf_iter_mptcp_subflow *it,
 			   struct mptcp_sock *msk)
 {
 	struct bpf_iter_mptcp_subflow_kern *kit = (void *)it;
+	struct sock *sk = (struct sock *)msk;
+
+	BUILD_BUG_ON(sizeof(struct bpf_iter_mptcp_subflow_kern) !=
+		     sizeof(struct bpf_iter_mptcp_subflow));
+	BUILD_BUG_ON(__alignof__(struct bpf_iter_mptcp_subflow_kern) !=
+		     __alignof__(struct bpf_iter_mptcp_subflow));
 
 	kit->msk = msk;
 	if (!msk)
 		return -EINVAL;
 
-	msk_owned_by_me(msk);
+	if (!sock_owned_by_user_nocheck(sk) &&
+	    !spin_is_locked(&sk->sk_lock.slock))
+		return -EINVAL;
 
 	kit->pos = &msk->conn_list;
 	return 0;
-- 
2.45.2

[PATCH mptcp-next v3 5/5] Squash to "selftests/bpf: Add mptcp_subflow bpf_iter subtest"

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Use bpf_skc_to_mptcp_sock() and mptcp_subflow_tcp_sock() instead of
bpf_mptcp_sk() and bpf_mptcp_subflow_tcp_sock().

IPPROTO_MPTCP is checked in bpf_skc_to_mptcp_sock(), no need to check
it in BPF program.

bpf_skc_to_mptcp_sock() and bpf_mptcp_subflow_ctx() may return NULL,
need to check the return values.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/bpf/progs/mptcp_bpf.h       |  1 -
 tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c | 11 +++++------
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf.h b/tools/testing/selftests/bpf/progs/mptcp_bpf.h
index 3b20cfd44505..b1f6e1fb467e 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf.h
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf.h
@@ -46,7 +46,6 @@ mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
 extern struct mptcp_sock *bpf_mptcp_sock_acquire(struct mptcp_sock *msk) __ksym;
 extern void bpf_mptcp_sock_release(struct mptcp_sock *msk) __ksym;
 
-extern struct mptcp_sock *bpf_mptcp_sk(struct sock *sk) __ksym;
 extern struct mptcp_subflow_context *
 bpf_mptcp_subflow_ctx(const struct sock *sk) __ksym;
 extern struct sock *
diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c
index 1bede22a7e3d..fd5691a4073b 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c
@@ -21,12 +21,11 @@ int iters_subflow(struct bpf_sockopt *ctx)
 	struct mptcp_sock *msk;
 	int local_ids = 0;
 
-	if (!sk || sk->protocol != IPPROTO_MPTCP ||
-	    ctx->level != SOL_TCP || ctx->optname != TCP_IS_MPTCP)
+	if (ctx->level != SOL_TCP || ctx->optname != TCP_IS_MPTCP)
 		return 1;
 
-	msk = bpf_mptcp_sk((struct sock *)sk);
-	if (msk->pm.server_side || !msk->pm.subflows)
+	msk = bpf_skc_to_mptcp_sock(sk);
+	if (!msk || msk->pm.server_side || !msk->pm.subflows)
 		return 1;
 
 	msk = bpf_mptcp_sock_acquire(msk);
@@ -41,7 +40,7 @@ int iters_subflow(struct bpf_sockopt *ctx)
 		local_ids += subflow->subflow_id;
 
 		/* only to check the following kfunc works */
-		ssk = bpf_mptcp_subflow_tcp_sock(subflow);
+		ssk = mptcp_subflow_tcp_sock(subflow);
 	}
 
 	if (!ssk)
@@ -53,7 +52,7 @@ int iters_subflow(struct bpf_sockopt *ctx)
 
 	/* only to check the following kfunc works */
 	subflow = bpf_mptcp_subflow_ctx(ssk);
-	if (subflow->token != msk->token)
+	if (!subflow || subflow->token != msk->token)
 		goto out;
 
 	ids = local_ids;
-- 
2.45.2

Re: [PATCH mptcp-next v3 0/5] Squash to "Add mptcp_subflow bpf_iter support"

[MPTCP CI]

Hi Geliang,

Thank you for your modifications, that's great!

But sadly, our CI spotted some issues with it when trying to build it.

You can find more details there:

  https://github.com/multipath-tcp/mptcp_net-next/actions/runs/12230234363

Status: failure
Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/c420a7ab2b44
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=915780

Feel free to reply to this email if you cannot access logs, if you need
some support to fix the error, if this doesn't seem to be caused by your
modifications or if the error is a false positive one.

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Re: [PATCH mptcp-next v3 0/5] Squash to "Add mptcp_subflow bpf_iter support"

[MPTCP CI]

Hi Geliang,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal: Critical: Global Timeout ❌
- KVM Validation: debug: Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/12230234356

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/c420a7ab2b44
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=915780


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

[PATCH mptcp-next v3 0/5] Squash to "Add mptcp_subflow bpf_iter support"

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

v3:
 - patch 3, continue to use sock_owned_by_user_nocheck() and spin_is_locked()
checks instead of using msk_owned_by_me().
 - patch 5, drop declaration of bpf_mptcp_subflow_tcp_sock. It's no longer
used.
 - patch 5, update the comment for mptcp_subflow_tcp_sock(), which is a BPF
helper, not a kfunc.

The commit log of "bpf: Register mptcp common kfunc set" doesn't match the
code, please update it as:

'''
bpf: Register mptcp common kfunc set

MPTCP helper mptcp_subflow_ctx() is used to convert struct sock to
struct mptcp_subflow_context. It will be used in MPTCP BPF programs.

This patch defines corresponding wrapper of this helper, and put it
into the newly defined mptcp common kfunc set and register this set
with the flag BPF_PROG_TYPE_CGROUP_SOCKOPT to let it accessible to
the 'cgroup/getsockopt' type of BPF programs.
'''

v2:
 - Drop bpf_skc_to_mptcp_sock
 - Check the owner before assigning the msk as Mat suggested.
 - Use bpf_core_cast() in mptcp_subflow bpf_iter subtest instead of
using bpf_skc_to_mptcp_sock().

Address Martin's suggestions for "Add mptcp_subflow bpf_iter support" v2.

Geliang Tang (5):
  Revert "bpf: Extend bpf_skc_to_mptcp_sock to MPTCP sock"
  Revert "bpf: Allow use of skc_to_mptcp_sock in cg_sockopt"
  Squash to "bpf: Add mptcp_subflow bpf_iter"
  Revert "bpf: Acquire and release mptcp socket"
  Squash to "selftests/bpf: Add mptcp_subflow bpf_iter subtest"

 include/net/mptcp.h                           |  4 +-
 kernel/bpf/cgroup.c                           |  2 -
 net/core/filter.c                             |  2 +-
 net/mptcp/bpf.c                               | 41 +++++--------------
 .../testing/selftests/bpf/bpf_experimental.h  |  2 +-
 tools/testing/selftests/bpf/progs/mptcp_bpf.h |  5 ---
 .../selftests/bpf/progs/mptcp_bpf_iters.c     | 10 ++---
 7 files changed, 17 insertions(+), 49 deletions(-)

-- 
2.43.0

Re: [PATCH mptcp-next v3 0/5] Squash to "Add mptcp_subflow bpf_iter support"

[MPTCP CI]

Hi Geliang,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal: Success! ✅
- KVM Validation: debug: Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/13368589515

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/c163f5827a44
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=934633


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)