Series comparison

-[PATCH mptcp-next v12 00/10] use bpf_iter in bpf schedulers
+[PATCH mptcp-next v13 0/9] use bpf_iter in bpf schedulers
 From: Geliang Tang <tanggeliang@kylinos.cn>
+v13:
+ - use '__ign' suffix to ignore the argument type checks of
+   bpf_mptcp_subflow_ctx() and bpf_sk_stream_memory_free(),
+   instead of adding a new helper bpf_mptcp_send_info_to_ssk().
+ - use 'bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk)' instead
+   of using 'bpf_for_each(mptcp_subflow, subflow, msk)'.
+ - keep struct mptcp_sched_data for future use.
+Depends on:
+ - Squash to "Add mptcp_subflow bpf_iter support", v2
+Based-on: <cover.1738470660.git.tanggeliang@kylinos.cn>
 v12:
  - drop struct mptcp_sched_data.
  - rebased on "split get_subflow interface into two" v2.
-Based-on: <cover.1734942318.git.tanggeliang@kylinos.cn>
 v11:
 If another squash-to patchset (Squash to "Add mptcp_subflow bpf_iter
 support") under review is merged before this set, v10 will fail to run.
 v11 fixes this issue and can run regardless of whether it is merged
 ...
 With the newly added mptcp_subflow bpf_iter, we can get rid of the
 subflows array "contexts" in struct mptcp_sched_data. This set
 uses bpf_for_each(mptcp_subflow) helper to update all the bpf
 schedules:
-        bpf_for_each(mptcp_subflow, subflow, msk) {
+        bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk) {
                 ... ...
                 mptcp_subflow_set_scheduled(subflow, true);
         }
-Geliang Tang (10):
+Geliang Tang (9):
-  bpf: Add bpf_mptcp_send_info_to_ssk
+  Squash to "bpf: Register mptcp common kfunc set"
   Revert "mptcp: add sched_data helpers"
-  mptcp: drop struct mptcp_sched_data
-  Squash to "bpf: Add bpf_mptcp_sched_ops"
   Squash to "bpf: Export mptcp packet scheduler helpers"
   Squash to "selftests/bpf: Add bpf_first scheduler & test"
   Squash to "selftests/bpf: Add bpf_bkup scheduler & test"
   Squash to "selftests/bpf: Add bpf_rr scheduler & test"
   Squash to "selftests/bpf: Add bpf_red scheduler & test"
   Squash to "selftests/bpf: Add bpf_burst scheduler & test"
+  mptcp: drop subflow contexts in mptcp_sched_data
- include/net/mptcp.h                           | 13 +---
+ include/net/mptcp.h                           |  3 -
- include/uapi/linux/bpf.h                      |  7 ++
+ net/mptcp/bpf.c                               | 52 +++++++------
- net/mptcp/bpf.c                               | 55 +++++++++------
+ net/mptcp/protocol.h                          |  2 -
- net/mptcp/protocol.c                          |  5 --
+ net/mptcp/sched.c                             | 22 ------
  net/mptcp/protocol.h                          |  7 +-
  net/mptcp/sched.c                             | 40 ++---------
  tools/include/uapi/linux/bpf.h                |  7 ++
  tools/testing/selftests/bpf/progs/mptcp_bpf.h |  3 -
- .../selftests/bpf/progs/mptcp_bpf_bkup.c      | 19 ++----
+ .../selftests/bpf/progs/mptcp_bpf_bkup.c      | 16 +---
- .../selftests/bpf/progs/mptcp_bpf_burst.c     | 68 +++++++------------
+ .../selftests/bpf/progs/mptcp_bpf_burst.c     | 78 +++++++------------
- .../selftests/bpf/progs/mptcp_bpf_first.c     | 11 ++-
+ .../selftests/bpf/progs/mptcp_bpf_first.c     |  8 +-
- .../selftests/bpf/progs/mptcp_bpf_red.c       | 11 ++-
+ .../selftests/bpf/progs/mptcp_bpf_red.c       |  8 +-
- .../selftests/bpf/progs/mptcp_bpf_rr.c        | 34 ++++------
+ .../selftests/bpf/progs/mptcp_bpf_rr.c        | 31 ++++----
-files changed, 119 insertions(+), 161 deletions(-)
+files changed, 80 insertions(+), 143 deletions(-)
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 01/10] bpf: Add bpf_mptcp_send_info_to_ssk
+Deleted patch
-From: Geliang Tang <tanggeliang@kylinos.cn>
-Burst scheduler needs to allocate an array of struct subflow_send_info
-on the stack and then select a subflow to send data. In order to implement
-burst scheduler in BPF, this patch adds a new bpf_mptcp_send_info_to_ssk()
-helper to get ssk from subflow_send_info and sets its parameter type as
-ARG_PTR_TO_STACK.
-Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
----
- include/uapi/linux/bpf.h       |  7 +++++++
- net/mptcp/bpf.c                | 22 ++++++++++++++++++++++
- net/mptcp/protocol.c           |  5 -----
- net/mptcp/protocol.h           |  5 +++++
- tools/include/uapi/linux/bpf.h |  7 +++++++
-files changed, 41 insertions(+), 5 deletions(-)
-diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
-index XXXXXXX..XXXXXXX 100644
---- a/include/uapi/linux/bpf.h
-+++ b/include/uapi/linux/bpf.h
-@@ -XXX,XX +XXX,XX @@ union bpf_attr {
-  *        0 on success.
-  *
-  *        **-ENOENT** if the bpf_local_storage cannot be found.
-+ *
-+ * void *bpf_mptcp_send_info_to_ssk(void *info)
-+ *    Description
-+ *        Dynamically cast a *info* pointer to a *sock* pointer.
-+ *    Return
-+ *        *info* if casting is valid, or **NULL** otherwise.
-  */
- #define ___BPF_FUNC_MAPPER(FN, ctx...)            \
-     FN(unspec, 0, ##ctx)                \
-@@ -XXX,XX +XXX,XX @@ union bpf_attr {
-     FN(user_ringbuf_drain, 209, ##ctx)        \
-     FN(cgrp_storage_get, 210, ##ctx)        \
-     FN(cgrp_storage_delete, 211, ##ctx)        \
-+    FN(mptcp_send_info_to_ssk, 212, ##ctx)        \
-     /* */
- /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't
-diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
-index XXXXXXX..XXXXXXX 100644
---- a/net/mptcp/bpf.c
-+++ b/net/mptcp/bpf.c
-@@ -XXX,XX +XXX,XX @@ static struct bpf_struct_ops bpf_mptcp_sched_ops;
- static const struct btf_type *mptcp_sock_type, *mptcp_subflow_type __read_mostly;
- static u32 mptcp_sock_id, mptcp_subflow_id;
-+BPF_CALL_1(bpf_mptcp_send_info_to_ssk, struct subflow_send_info *, info)
-+{
-+    BTF_TYPE_EMIT(struct sock);
-+
-+    if (info && info->ssk && sk_fullsock(info->ssk) &&
-+        info->ssk->sk_protocol == IPPROTO_TCP &&
-+        sk_is_mptcp(info->ssk))
-+        return (unsigned long)info->ssk;
-+
-+    return (unsigned long)NULL;
-+}
-+
-+static const struct bpf_func_proto bpf_mptcp_send_info_to_ssk_proto = {
-+    .func        = bpf_mptcp_send_info_to_ssk,
-+    .gpl_only    = false,
-+    .ret_type    = RET_PTR_TO_BTF_ID_OR_NULL,
-+    .arg1_type    = ARG_PTR_TO_STACK,
-+    .ret_btf_id    = &btf_sock_ids[BTF_SOCK_TYPE_SOCK],
-+};
-+
- static const struct bpf_func_proto *
- bpf_mptcp_sched_get_func_proto(enum bpf_func_id func_id,
-                    const struct bpf_prog *prog)
-@@ -XXX,XX +XXX,XX @@ bpf_mptcp_sched_get_func_proto(enum bpf_func_id func_id,
-         return &bpf_skc_to_tcp6_sock_proto;
-     case BPF_FUNC_skc_to_tcp_sock:
-         return &bpf_skc_to_tcp_sock_proto;
-+    case BPF_FUNC_mptcp_send_info_to_ssk:
-+        return &bpf_mptcp_send_info_to_ssk_proto;
-     default:
-         return bpf_base_func_proto(func_id, prog);
-     }
-diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
-index XXXXXXX..XXXXXXX 100644
---- a/net/mptcp/protocol.c
-+++ b/net/mptcp/protocol.c
-@@ -XXX,XX +XXX,XX @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
-                      sizeof(struct ipv6hdr) - \
-                      sizeof(struct frag_hdr))
--struct subflow_send_info {
--    struct sock *ssk;
--    u64 linger_time;
--};
--
- void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow)
- {
-     if (!subflow->stale)
-diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
-index XXXXXXX..XXXXXXX 100644
---- a/net/mptcp/protocol.h
-+++ b/net/mptcp/protocol.h
-@@ -XXX,XX +XXX,XX @@ mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
-     WRITE_ONCE(subflow->local_id, -1);
- }
-+struct subflow_send_info {
-+    struct sock *ssk;
-+    u64 linger_time;
-+};
-+
- /* Convert reset reasons in MPTCP to enum sk_rst_reason type */
- static inline enum sk_rst_reason
- sk_rst_convert_mptcp_reason(u32 reason)
-diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
-index XXXXXXX..XXXXXXX 100644
---- a/tools/include/uapi/linux/bpf.h
-+++ b/tools/include/uapi/linux/bpf.h
-@@ -XXX,XX +XXX,XX @@ union bpf_attr {
-  *        0 on success.
-  *
-  *        **-ENOENT** if the bpf_local_storage cannot be found.
-+ *
-+ * void *bpf_mptcp_send_info_to_ssk(void *info)
-+ *    Description
-+ *        Dynamically cast a *info* pointer to a *sock* pointer.
-+ *    Return
-+ *        *info* if casting is valid, or **NULL** otherwise.
-  */
- #define ___BPF_FUNC_MAPPER(FN, ctx...)            \
-     FN(unspec, 0, ##ctx)                \
-@@ -XXX,XX +XXX,XX @@ union bpf_attr {
-     FN(user_ringbuf_drain, 209, ##ctx)        \
-     FN(cgrp_storage_get, 210, ##ctx)        \
-     FN(cgrp_storage_delete, 211, ##ctx)        \
-+    FN(mptcp_send_info_to_ssk, 212, ##ctx)        \
-     /* */
- /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't
---
-.45.2

-[PATCH mptcp-next v12 04/10] Squash to "bpf: Add bpf_mptcp_sched_ops"
+[PATCH mptcp-next v13 1/9] Squash to "bpf: Register mptcp common kfunc set"
 From: Geliang Tang <tanggeliang@kylinos.cn>
-Please update the subject to
+Instead of adding a new BPF function bpf_mptcp_send_info_to_ssk() in
+v12, this patch uses a much more simpler approach, which using '__ign'
-        bpf: Add mptcp packet scheduler struct_ops
+suffix for the argument of bpf_mptcp_subflow_ctx() to let BPF to
+ignore the type check of this argument.
 Drop struct mptcp_sched_data.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- net/mptcp/bpf.c | 6 ++----
+ net/mptcp/bpf.c | 8 ++++----
-file changed, 2 insertions(+), 4 deletions(-)
+file changed, 4 insertions(+), 4 deletions(-)
 diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/bpf.c
 +++ b/net/mptcp/bpf.c
-@@ -XXX,XX +XXX,XX @@ static int bpf_mptcp_sched_init(struct btf *btf)
+@@ -XXX,XX +XXX,XX @@ struct bpf_iter_mptcp_subflow_kern {
-     return 0;
+ __bpf_kfunc_start_defs();
- }
+ __bpf_kfunc static struct mptcp_subflow_context *
--static int __bpf_mptcp_sched_get_send(struct mptcp_sock *msk,
+-bpf_mptcp_subflow_ctx(const struct sock *sk)
--                      struct mptcp_sched_data *data)
++bpf_mptcp_subflow_ctx(const struct sock *sk__ign)
 +static int __bpf_mptcp_sched_get_send(struct mptcp_sock *msk)
  {
-     return 0;
+-    if (sk && sk_fullsock(sk) &&
- }
+-        sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk))
+-        return mptcp_subflow_ctx(sk);
--static int __bpf_mptcp_sched_get_retrans(struct mptcp_sock *msk,
++    if (sk__ign && sk_fullsock(sk__ign) &&
--                     struct mptcp_sched_data *data)
++        sk__ign->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk__ign))
-+static int __bpf_mptcp_sched_get_retrans(struct mptcp_sock *msk)
++        return mptcp_subflow_ctx(sk__ign);
- {
-     return 0;
+     return NULL;
  }
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 02/10] Revert "mptcp: add sched_data helpers"
+[PATCH mptcp-next v13 2/9] Revert "mptcp: add sched_data helpers"
 ...
 diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/bpf.c
 +++ b/net/mptcp/bpf.c
-@@ -XXX,XX +XXX,XX @@ __bpf_kfunc static void bpf_mptcp_sock_release(struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subflow *it)
-     WARN_ON_ONCE(!sk || !refcount_dec_not_one(&sk->sk_refcnt));
+ {
  }
 -__bpf_kfunc struct mptcp_subflow_context *
 -bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos)
 -{
 ...
 -    mptcp_sched_data_set_contexts(msk, &data);
      return msk->sched->get_send(msk, &data);
  }
 @@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_retrans(struct mptcp_sock *msk)
      if (msk->sched == &mptcp_sched_default || !msk->sched)
          return mptcp_sched_default_get_retrans(msk, &data);
 -    mptcp_sched_data_set_contexts(msk, &data);
-     if (!msk->sched->get_retrans)
+     if (msk->sched->get_retrans)
-         return msk->sched->get_send(msk, &data);
+         return msk->sched->get_retrans(msk, &data);
-     return msk->sched->get_retrans(msk, &data);
+     return msk->sched->get_send(msk, &data);
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 05/10] Squash to "bpf: Export mptcp packet scheduler helpers"
+[PATCH mptcp-next v13 3/9] Squash to "bpf: Export mptcp packet scheduler helpers"
 From: Geliang Tang <tanggeliang@kylinos.cn>
 Remove bpf_mptcp_subflow_ctx_by_pos from BPF kfunc set.
 Drop bpf_mptcp_sched_kfunc_set, use bpf_mptcp_common_kfunc_set instead.
+Add new helpers bpf_mptcp_subflow_tcp_sock() and
+bpf_sk_stream_memory_free().
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- net/mptcp/bpf.c | 27 ++++++++++++++-------------
+ net/mptcp/bpf.c | 38 ++++++++++++++++++++++++--------------
-file changed, 14 insertions(+), 13 deletions(-)
+file changed, 24 insertions(+), 14 deletions(-)
 diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/bpf.c
 +++ b/net/mptcp/bpf.c
-@@ -XXX,XX +XXX,XX @@ __bpf_kfunc static void bpf_mptcp_sock_release(struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ bpf_mptcp_subflow_ctx(const struct sock *sk__ign)
-     WARN_ON_ONCE(!sk || !refcount_dec_not_one(&sk->sk_refcnt));
+     return NULL;
  }
 +__bpf_kfunc static struct sock *
 +bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
 +{
 +    if (!subflow)
 +        return NULL;
 +
 +    return mptcp_subflow_tcp_sock(subflow);
 +}
 +
- __bpf_kfunc static bool bpf_mptcp_subflow_queues_empty(struct sock *sk)
+ __bpf_kfunc static int
- {
+ bpf_iter_mptcp_subflow_new(struct bpf_iter_mptcp_subflow *it,
                 struct sock *sk)
@@ -XXX,XX +XXX,XX @@ __bpf_kfunc static bool bpf_mptcp_subflow_queues_empty(struct sock *sk)
      return tcp_rtx_queue_empty(sk);
-@@ -XXX,XX +XXX,XX @@ BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_next, KF_ITER_NEXT | KF_RET_NULL)
+ }
 +__bpf_kfunc static bool bpf_sk_stream_memory_free(const struct sock *sk__ign)
 +{
 +    if (sk__ign && sk_fullsock(sk__ign) &&
 +        sk__ign->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk__ign))
 +        return sk_stream_memory_free(sk__ign);
 +
 +    return NULL;
 +}
 +
  __bpf_kfunc_end_defs();
  BTF_KFUNCS_START(bpf_mptcp_common_kfunc_ids)
  BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx, KF_RET_NULL)
 +BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock, 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)
- BTF_ID_FLAGS(func, bpf_mptcp_sock_acquire, KF_ACQUIRE | KF_RET_NULL)
- BTF_ID_FLAGS(func, bpf_mptcp_sock_release, KF_RELEASE)
 -BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids)
 -
 -static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set = {
 -    .owner    = THIS_MODULE,
 -    .set    = &bpf_mptcp_common_kfunc_ids,
 ...
  BTF_ID_FLAGS(func, mptcp_subflow_set_scheduled)
 -BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx_by_pos)
  BTF_ID_FLAGS(func, mptcp_subflow_active)
  BTF_ID_FLAGS(func, mptcp_set_timeout)
  BTF_ID_FLAGS(func, mptcp_wnd_end)
- BTF_ID_FLAGS(func, tcp_stream_memory_free)
+-BTF_ID_FLAGS(func, tcp_stream_memory_free)
 +BTF_ID_FLAGS(func, bpf_sk_stream_memory_free, KF_RET_NULL)
  BTF_ID_FLAGS(func, bpf_mptcp_subflow_queues_empty)
-+BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock, KF_RET_NULL)
  BTF_ID_FLAGS(func, mptcp_pm_subflow_chk_stale, KF_SLEEPABLE)
 -BTF_KFUNCS_END(bpf_mptcp_sched_kfunc_ids)
 +BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids)
 -static const struct btf_kfunc_id_set bpf_mptcp_sched_kfunc_set = {
 ...
 +                           &bpf_mptcp_common_kfunc_set);
  #ifdef CONFIG_BPF_JIT
      ret = ret ?: register_bpf_struct_ops(&bpf_mptcp_sched_ops, mptcp_sched_ops);
  #endif
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 06/10] Squash to "selftests/bpf: Add bpf_first scheduler & test"
+[PATCH mptcp-next v13 4/9] Squash to "selftests/bpf: Add bpf_first scheduler & test"
 From: Geliang Tang <tanggeliang@kylinos.cn>
 Use the newly added bpf_for_each() helper to walk the conn_list.
 Drop bpf_mptcp_subflow_ctx_by_pos declaration.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- tools/testing/selftests/bpf/progs/mptcp_bpf.h       |  3 ---
+ tools/testing/selftests/bpf/progs/mptcp_bpf.h       | 3 ---
- tools/testing/selftests/bpf/progs/mptcp_bpf_first.c | 11 ++++++++---
+ tools/testing/selftests/bpf/progs/mptcp_bpf_first.c | 8 +++++++-
-files changed, 8 insertions(+), 6 deletions(-)
+files changed, 7 insertions(+), 4 deletions(-)
 diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf.h b/tools/testing/selftests/bpf/progs/mptcp_bpf.h
 index XXXXXXX..XXXXXXX 100644
 --- a/tools/testing/selftests/bpf/progs/mptcp_bpf.h
 +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf.h
 ...
  #endif
 diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
 +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
-@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_first_release, struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
- }
+ int BPF_PROG(bpf_first_get_send, struct mptcp_sock *msk,
+          struct mptcp_sched_data *data)
  SEC("struct_ops")
 -int BPF_PROG(bpf_first_get_send, struct mptcp_sock *msk,
 -         struct mptcp_sched_data *data)
 +int BPF_PROG(bpf_first_get_send, struct mptcp_sock *msk)
  {
 -    mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, 0), true);
 +    struct mptcp_subflow_context *subflow;
 +
 +    subflow = bpf_mptcp_subflow_ctx(msk->first);
 ...
 +    mptcp_subflow_set_scheduled(subflow, true);
      return 0;
  }
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 07/10] Squash to "selftests/bpf: Add bpf_bkup scheduler & test"
+[PATCH mptcp-next v13 5/9] Squash to "selftests/bpf: Add bpf_bkup scheduler & test"
 From: Geliang Tang <tanggeliang@kylinos.cn>
 Use the newly added bpf_for_each() helper to walk the conn_list.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- .../selftests/bpf/progs/mptcp_bpf_bkup.c      | 19 ++++---------------
+ .../testing/selftests/bpf/progs/mptcp_bpf_bkup.c | 16 +++-------------
-file changed, 4 insertions(+), 15 deletions(-)
+file changed, 3 insertions(+), 13 deletions(-)
 diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
 +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
-@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_bkup_release, struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
- }
+ int BPF_PROG(bpf_bkup_get_send, struct mptcp_sock *msk,
+          struct mptcp_sched_data *data)
  SEC("struct_ops")
 -int BPF_PROG(bpf_bkup_get_send, struct mptcp_sock *msk,
 -         struct mptcp_sched_data *data)
 +int BPF_PROG(bpf_bkup_get_send, struct mptcp_sock *msk)
  {
 -    int nr = -1;
 -
 -    for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
 -        struct mptcp_subflow_context *subflow;
 -
 -        subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
 -        if (!subflow)
 -            break;
 +    struct mptcp_subflow_context *subflow;
-+    bpf_for_each(mptcp_subflow, subflow, msk) {
++    bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk) {
          if (!BPF_CORE_READ_BITFIELD_PROBED(subflow, backup) ||
              !BPF_CORE_READ_BITFIELD_PROBED(subflow, request_bkup)) {
 -            nr = i;
 +            mptcp_subflow_set_scheduled(subflow, true);
              break;
 ...
 -    }
      return 0;
  }
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 08/10] Squash to "selftests/bpf: Add bpf_rr scheduler & test"
+[PATCH mptcp-next v13 6/9] Squash to "selftests/bpf: Add bpf_rr scheduler & test"
 From: Geliang Tang <tanggeliang@kylinos.cn>
 Use the newly added bpf_for_each() helper to walk the conn_list.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- .../selftests/bpf/progs/mptcp_bpf_rr.c        | 34 ++++++++-----------
+ .../selftests/bpf/progs/mptcp_bpf_rr.c        | 31 +++++++++----------
-file changed, 15 insertions(+), 19 deletions(-)
+file changed, 14 insertions(+), 17 deletions(-)
 diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
 +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
-@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_rr_release, struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
- }
+ int BPF_PROG(bpf_rr_get_send, struct mptcp_sock *msk,
+          struct mptcp_sched_data *data)
  SEC("struct_ops")
 -int BPF_PROG(bpf_rr_get_send, struct mptcp_sock *msk,
 -         struct mptcp_sched_data *data)
 +int BPF_PROG(bpf_rr_get_send, struct mptcp_sock *msk)
  {
 -    struct mptcp_subflow_context *subflow;
 +    struct mptcp_subflow_context *subflow, *next;
      struct mptcp_rr_storage *ptr;
 -    struct sock *last_snd = NULL;
 ...
 +        goto out;
 -        if (mptcp_subflow_tcp_sock(subflow) == last_snd) {
 -            if (i + 1 == MPTCP_SUBFLOWS_MAX ||
 -                !bpf_mptcp_subflow_ctx_by_pos(data, i + 1))
-+    bpf_for_each(mptcp_subflow, subflow, msk) {
++    bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk) {
 +        if (mptcp_subflow_tcp_sock(subflow) == ptr->last_snd) {
 +            subflow = bpf_iter_mptcp_subflow_next(&___it);
 +            if (!subflow)
                  break;
 ...
 +    ptr->last_snd = mptcp_subflow_tcp_sock(next);
      return 0;
  }
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 09/10] Squash to "selftests/bpf: Add bpf_red scheduler & test"
+[PATCH mptcp-next v13 7/9] Squash to "selftests/bpf: Add bpf_red scheduler & test"
 From: Geliang Tang <tanggeliang@kylinos.cn>
 Use the newly added bpf_for_each() helper to walk the conn_list.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- tools/testing/selftests/bpf/progs/mptcp_bpf_red.c | 11 ++++-------
+ tools/testing/selftests/bpf/progs/mptcp_bpf_red.c | 8 +++-----
-file changed, 4 insertions(+), 7 deletions(-)
+file changed, 3 insertions(+), 5 deletions(-)
 diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
 +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
-@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_red_release, struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
- }
+ int BPF_PROG(bpf_red_get_send, struct mptcp_sock *msk,
+          struct mptcp_sched_data *data)
  SEC("struct_ops")
 -int BPF_PROG(bpf_red_get_send, struct mptcp_sock *msk,
 -         struct mptcp_sched_data *data)
 +int BPF_PROG(bpf_red_get_send, struct mptcp_sock *msk)
  {
 -    for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
 -        if (!bpf_mptcp_subflow_ctx_by_pos(data, i))
 -            break;
 +    struct mptcp_subflow_context *subflow;
 -        mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, i), true);
 -    }
-+    bpf_for_each(mptcp_subflow, subflow, msk)
++    bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk)
 +        mptcp_subflow_set_scheduled(subflow, true);
      return 0;
  }
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 10/10] Squash to "selftests/bpf: Add bpf_burst scheduler & test"
+[PATCH mptcp-next v13 8/9] Squash to "selftests/bpf: Add bpf_burst scheduler & test"
 From: Geliang Tang <tanggeliang@kylinos.cn>
 Use the newly added bpf_for_each() helper to walk the conn_list.
-Use bpf_mptcp_send_info_to_ssk() helper.
 Drop bpf_subflow_send_info, use subflow_send_info instead.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- .../selftests/bpf/progs/mptcp_bpf_burst.c     | 68 +++++++------------
+ .../selftests/bpf/progs/mptcp_bpf_burst.c     | 78 +++++++------------
-file changed, 26 insertions(+), 42 deletions(-)
+file changed, 26 insertions(+), 52 deletions(-)
 diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
 +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
 ...
 -};
 -
  extern bool mptcp_subflow_active(struct mptcp_subflow_context *subflow) __ksym;
  extern void mptcp_set_timeout(struct sock *sk) __ksym;
  extern __u64 mptcp_wnd_end(const struct mptcp_sock *msk) __ksym;
-@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_burst_release, struct mptcp_sock *msk)
+-extern bool tcp_stream_memory_free(const struct sock *sk, int wake) __ksym;
 +extern bool bpf_sk_stream_memory_free(const struct sock *sk) __ksym;
  extern bool bpf_mptcp_subflow_queues_empty(struct sock *sk) __ksym;
  extern void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk) __ksym;
@@ -XXX,XX +XXX,XX @@ static __always_inline bool tcp_rtx_and_write_queues_empty(struct sock *sk)
      return bpf_mptcp_subflow_queues_empty(sk) && tcp_write_queue_empty(sk);
  }
+-static __always_inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
+-{
+-    if (sk->sk_wmem_queued >= sk->sk_sndbuf)
+-        return false;
+-
+-    return tcp_stream_memory_free(sk, wake);
+-}
+-
+-static __always_inline bool sk_stream_memory_free(const struct sock *sk)
+-{
+-    return __sk_stream_memory_free(sk, 0);
+-}
+-
  SEC("struct_ops")
--int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
+ void BPF_PROG(mptcp_sched_burst_init, struct mptcp_sock *msk)
--         struct mptcp_sched_data *data)
+ {
-+int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk)
+@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
  int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
           struct mptcp_sched_data *data)
  {
 -    struct bpf_subflow_send_info send_info[SSK_MODE_MAX];
 +    struct subflow_send_info send_info[SSK_MODE_MAX];
      struct mptcp_subflow_context *subflow;
      struct sock *sk = (struct sock *)msk;
 ...
 -        subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
 -        if (!subflow)
 -            break;
 -
 -        backup = subflow->backup || subflow->request_bkup;
-+    bpf_for_each(mptcp_subflow, subflow, msk) {
++    bpf_for_each(mptcp_subflow, subflow, sk) {
 +        bool backup = subflow->backup || subflow->request_bkup;
          ssk = mptcp_subflow_tcp_sock(subflow);
          if (!mptcp_subflow_active(subflow))
 @@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 ...
 -        send_info[SSK_MODE_ACTIVE].subflow_id = send_info[SSK_MODE_BACKUP].subflow_id;
 +        send_info[SSK_MODE_ACTIVE].ssk = send_info[SSK_MODE_BACKUP].ssk;
 -    subflow = bpf_mptcp_subflow_ctx_by_pos(data, send_info[SSK_MODE_ACTIVE].subflow_id);
 -    if (!subflow)
--        return -1;
++    ssk = send_info[SSK_MODE_ACTIVE].ssk;
 +    if (!ssk || !bpf_sk_stream_memory_free(ssk))
          return -1;
 -    ssk = mptcp_subflow_tcp_sock(subflow);
-+    ssk = bpf_mptcp_send_info_to_ssk(&send_info[SSK_MODE_ACTIVE]);
+-    if (!ssk || !sk_stream_memory_free(ssk))
-     if (!ssk || !sk_stream_memory_free(ssk))
++
          return -1;
 +    subflow = bpf_mptcp_subflow_ctx(ssk);
 +    if (!subflow)
-+        return -1;
+         return -1;
-+
      burst = min(MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt);
++    ssk = bpf_core_cast(ssk, struct sock);
      wmem = ssk->sk_wmem_queued;
      if (!burst)
-@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
+         goto out;
- }
+@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
+ int BPF_PROG(bpf_burst_get_retrans, struct mptcp_sock *msk,
- SEC("struct_ops")
+          struct mptcp_sched_data *data)
 -int BPF_PROG(bpf_burst_get_retrans, struct mptcp_sock *msk,
 -         struct mptcp_sched_data *data)
 +int BPF_PROG(bpf_burst_get_retrans, struct mptcp_sock *msk)
  {
 -    int backup = MPTCP_SUBFLOWS_MAX, pick = MPTCP_SUBFLOWS_MAX, subflow_id;
 +    struct sock *backup = NULL, *pick = NULL;
      struct mptcp_subflow_context *subflow;
      int min_stale_count = INT_MAX;
 -    struct sock *ssk;
 -    for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
 -        subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
 -        if (!subflow)
 -            break;
-+    bpf_for_each(mptcp_subflow, subflow, msk) {
++    bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk) {
 +        struct sock *ssk = bpf_mptcp_subflow_tcp_sock(subflow);
 -        if (!mptcp_subflow_active(subflow))
 +        if (!ssk || !mptcp_subflow_active(subflow))
              continue;
 ...
 +    subflow = bpf_mptcp_subflow_ctx(pick);
      if (!subflow)
          return -1;
      mptcp_subflow_set_scheduled(subflow, true);
 --
-.45.2
+.43.0

-[PATCH mptcp-next v12 03/10] mptcp: drop struct mptcp_sched_data
+[PATCH mptcp-next v13 9/9] mptcp: drop subflow contexts in mptcp_sched_data
 ...
 The mptcp_subflow bpf_iter is added now, it's better to use the helper
 bpf_for_each(mptcp_subflow) to traverse all subflows on the conn_list of
 an MPTCP socket and then call kfunc to modify the fields of each subflow
 in the WIP MPTCP BPF packet scheduler examples, instead of converting them
 to a fixed array. With this helper, we can get rid of this subflow array
-"contexts" and the size of it "subflows" in struct mptcp_sched_data. Then
+"contexts" in struct mptcp_sched_data.
 the entire struct mptcp_sched_data can be dropped.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- include/net/mptcp.h | 13 ++-----------
+ include/net/mptcp.h | 3 ---
- net/mptcp/sched.c   | 18 +++++++-----------
+file changed, 3 deletions(-)
 files changed, 9 insertions(+), 22 deletions(-)
 diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/net/mptcp.h
 +++ b/include/net/mptcp.h
 @@ -XXX,XX +XXX,XX @@ struct mptcp_out_options {
  #define MPTCP_SCHED_MAX        128
  #define MPTCP_SCHED_BUF_MAX    (MPTCP_SCHED_NAME_MAX * MPTCP_SCHED_MAX)
 -#define MPTCP_SUBFLOWS_MAX    8
 -
--struct mptcp_sched_data {
+ struct mptcp_sched_data {
--    u8    subflows;
+     u8    subflows;
 -    struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
--};
+ };
--
  struct mptcp_sched_ops {
--    int (*get_send)(struct mptcp_sock *msk,
--            struct mptcp_sched_data *data);
--    int (*get_retrans)(struct mptcp_sock *msk,
--               struct mptcp_sched_data *data);
-+    int (*get_send)(struct mptcp_sock *msk);
-+    int (*get_retrans)(struct mptcp_sock *msk);
-     char            name[MPTCP_SCHED_NAME_MAX];
-     struct module        *owner;
-diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
-index XXXXXXX..XXXXXXX 100644
---- a/net/mptcp/sched.c
-+++ b/net/mptcp/sched.c
-@@ -XXX,XX +XXX,XX @@
- static DEFINE_SPINLOCK(mptcp_sched_list_lock);
- static LIST_HEAD(mptcp_sched_list);
--static int mptcp_sched_default_get_send(struct mptcp_sock *msk,
--                    struct mptcp_sched_data *data)
-+static int mptcp_sched_default_get_send(struct mptcp_sock *msk)
- {
-     struct sock *ssk;
-@@ -XXX,XX +XXX,XX @@ static int mptcp_sched_default_get_send(struct mptcp_sock *msk,
-     return 0;
- }
--static int mptcp_sched_default_get_retrans(struct mptcp_sock *msk,
--                       struct mptcp_sched_data *data)
-+static int mptcp_sched_default_get_retrans(struct mptcp_sock *msk)
- {
-     struct sock *ssk;
-@@ -XXX,XX +XXX,XX @@ void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
- int mptcp_sched_get_send(struct mptcp_sock *msk)
- {
-     struct mptcp_subflow_context *subflow;
--    struct mptcp_sched_data data;
-     msk_owned_by_me(msk);
-@@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_send(struct mptcp_sock *msk)
-     }
-     if (msk->sched == &mptcp_sched_default || !msk->sched)
--        return mptcp_sched_default_get_send(msk, &data);
--    return msk->sched->get_send(msk, &data);
-+        return mptcp_sched_default_get_send(msk);
-+    return msk->sched->get_send(msk);
- }
- int mptcp_sched_get_retrans(struct mptcp_sock *msk)
- {
-     struct mptcp_subflow_context *subflow;
--    struct mptcp_sched_data data;
-     msk_owned_by_me(msk);
-@@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_retrans(struct mptcp_sock *msk)
-     }
-     if (msk->sched == &mptcp_sched_default || !msk->sched)
--        return mptcp_sched_default_get_retrans(msk, &data);
-+        return mptcp_sched_default_get_retrans(msk);
-     if (!msk->sched->get_retrans)
--        return msk->sched->get_send(msk, &data);
--    return msk->sched->get_retrans(msk, &data);
-+        return msk->sched->get_send(msk);
-+    return msk->sched->get_retrans(msk);
- }
 --
-.45.2
+.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

v12:
 - drop struct mptcp_sched_data.
 - rebased on "split get_subflow interface into two" v2.

Based-on: <cover.1734942318.git.tanggeliang@kylinos.cn>

v11:
If another squash-to patchset (Squash to "Add mptcp_subflow bpf_iter
support") under review is merged before this set, v10 will fail to run.
v11 fixes this issue and can run regardless of whether it is merged
before or after the squash-to patchset.

Compared with v10, only patches 3, 5, and 8 have been modified:
 - use mptcp_subflow_tcp_sock instead of bpf_mptcp_subflow_tcp_sock in
   patch 3 and patch 5.
 - drop bpf_mptcp_sched_kfunc_set, use bpf_mptcp_common_kfunc_set instead
   in patch 8.

v10:
 - drop mptcp_subflow_set_scheduled() helper and WRITE_ONCE() in BPF.
 - add new bpf helper bpf_mptcp_send_info_to_ssk() for burst scheduler.

v9:
 - merge 'Fixes for "use bpf_iter in bpf schedulers" v8' into this set.
 - rebased on "add netns helpers" v4

v8:
 - address Mat's comments in v7.
 - move sk_stream_memory_free check inside bpf_for_each() loop.
 - implement mptcp_subflow_set_scheduled helper in BPF.
 - add cleanup patches into this set again.

v7:
 - move cleanup patches out of this set.
 - rebased.

v6:
 - rebased to "add mptcp_subflow bpf_iter" v10

v5:
 - patch 2, drop mptcp_sock_type and mptcp_subflow_type.
 - patch 3, revert "bpf: Export more bpf_burst related functions"
 - patch 4, merge "bpf: Export more bpf_burst related functions" into it.

v4:
 - patch 2, a new cleanup for "bpf: Add bpf_mptcp_sched_ops".
 - patch 3 should be reverted.
 - patch 8, register kfunc_set.

v3:
 - rebased.
 - put the "drop has_bytes_sent" squash-to patch into this set.

v2:
 - update bpf_rr and bpf_burst

With the newly added mptcp_subflow bpf_iter, we can get rid of the
subflows array "contexts" in struct mptcp_sched_data. This set
uses bpf_for_each(mptcp_subflow) helper to update all the bpf
schedules:

bpf_for_each(mptcp_subflow, subflow, msk) {
                ... ...
                mptcp_subflow_set_scheduled(subflow, true);
        }

Geliang Tang (10):
  bpf: Add bpf_mptcp_send_info_to_ssk
  Revert "mptcp: add sched_data helpers"
  mptcp: drop struct mptcp_sched_data
  Squash to "bpf: Add bpf_mptcp_sched_ops"
  Squash to "bpf: Export mptcp packet scheduler helpers"
  Squash to "selftests/bpf: Add bpf_first scheduler & test"
  Squash to "selftests/bpf: Add bpf_bkup scheduler & test"
  Squash to "selftests/bpf: Add bpf_rr scheduler & test"
  Squash to "selftests/bpf: Add bpf_red scheduler & test"
  Squash to "selftests/bpf: Add bpf_burst scheduler & test"

include/net/mptcp.h                           | 13 +---
 include/uapi/linux/bpf.h                      |  7 ++
 net/mptcp/bpf.c                               | 55 +++++++++------
 net/mptcp/protocol.c                          |  5 --
 net/mptcp/protocol.h                          |  7 +-
 net/mptcp/sched.c                             | 40 ++---------
 tools/include/uapi/linux/bpf.h                |  7 ++
 tools/testing/selftests/bpf/progs/mptcp_bpf.h |  3 -
 .../selftests/bpf/progs/mptcp_bpf_bkup.c      | 19 ++----
 .../selftests/bpf/progs/mptcp_bpf_burst.c     | 68 +++++++------------
 .../selftests/bpf/progs/mptcp_bpf_first.c     | 11 ++-
 .../selftests/bpf/progs/mptcp_bpf_red.c       | 11 ++-
 .../selftests/bpf/progs/mptcp_bpf_rr.c        | 34 ++++------
 13 files changed, 119 insertions(+), 161 deletions(-)

-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

Burst scheduler needs to allocate an array of struct subflow_send_info
on the stack and then select a subflow to send data. In order to implement
burst scheduler in BPF, this patch adds a new bpf_mptcp_send_info_to_ssk()
helper to get ssk from subflow_send_info and sets its parameter type as
ARG_PTR_TO_STACK.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/uapi/linux/bpf.h       |  7 +++++++
 net/mptcp/bpf.c                | 22 ++++++++++++++++++++++
 net/mptcp/protocol.c           |  5 -----
 net/mptcp/protocol.h           |  5 +++++
 tools/include/uapi/linux/bpf.h |  7 +++++++
 5 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index XXXXXXX..XXXXXXX 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -XXX,XX +XXX,XX @@ union bpf_attr {
  *		0 on success.
  *
  *		**-ENOENT** if the bpf_local_storage cannot be found.
+ *
+ * void *bpf_mptcp_send_info_to_ssk(void *info)
+ *	Description
+ *		Dynamically cast a *info* pointer to a *sock* pointer.
+ *	Return
+ *		*info* if casting is valid, or **NULL** otherwise.
  */
 #define ___BPF_FUNC_MAPPER(FN, ctx...)			\
 	FN(unspec, 0, ##ctx)				\
@@ -XXX,XX +XXX,XX @@ union bpf_attr {
 	FN(user_ringbuf_drain, 209, ##ctx)		\
 	FN(cgrp_storage_get, 210, ##ctx)		\
 	FN(cgrp_storage_delete, 211, ##ctx)		\
+	FN(mptcp_send_info_to_ssk, 212, ##ctx)		\
 	/* */
 
 /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -XXX,XX +XXX,XX @@ static struct bpf_struct_ops bpf_mptcp_sched_ops;
 static const struct btf_type *mptcp_sock_type, *mptcp_subflow_type __read_mostly;
 static u32 mptcp_sock_id, mptcp_subflow_id;
 
+BPF_CALL_1(bpf_mptcp_send_info_to_ssk, struct subflow_send_info *, info)
+{
+	BTF_TYPE_EMIT(struct sock);
+
+	if (info && info->ssk && sk_fullsock(info->ssk) &&
+	    info->ssk->sk_protocol == IPPROTO_TCP &&
+	    sk_is_mptcp(info->ssk))
+		return (unsigned long)info->ssk;
+
+	return (unsigned long)NULL;
+}
+
+static const struct bpf_func_proto bpf_mptcp_send_info_to_ssk_proto = {
+	.func		= bpf_mptcp_send_info_to_ssk,
+	.gpl_only	= false,
+	.ret_type	= RET_PTR_TO_BTF_ID_OR_NULL,
+	.arg1_type	= ARG_PTR_TO_STACK,
+	.ret_btf_id	= &btf_sock_ids[BTF_SOCK_TYPE_SOCK],
+};
+
 static const struct bpf_func_proto *
 bpf_mptcp_sched_get_func_proto(enum bpf_func_id func_id,
 			       const struct bpf_prog *prog)
@@ -XXX,XX +XXX,XX @@ bpf_mptcp_sched_get_func_proto(enum bpf_func_id func_id,
 		return &bpf_skc_to_tcp6_sock_proto;
 	case BPF_FUNC_skc_to_tcp_sock:
 		return &bpf_skc_to_tcp_sock_proto;
+	case BPF_FUNC_mptcp_send_info_to_ssk:
+		return &bpf_mptcp_send_info_to_ssk_proto;
 	default:
 		return bpf_base_func_proto(func_id, prog);
 	}
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -XXX,XX +XXX,XX @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
 					 sizeof(struct ipv6hdr) - \
 					 sizeof(struct frag_hdr))
 
-struct subflow_send_info {
-	struct sock *ssk;
-	u64 linger_time;
-};
-
 void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow)
 {
 	if (!subflow->stale)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -XXX,XX +XXX,XX @@ mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
 	WRITE_ONCE(subflow->local_id, -1);
 }
 
+struct subflow_send_info {
+	struct sock *ssk;
+	u64 linger_time;
+};
+
 /* Convert reset reasons in MPTCP to enum sk_rst_reason type */
 static inline enum sk_rst_reason
 sk_rst_convert_mptcp_reason(u32 reason)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index XXXXXXX..XXXXXXX 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -XXX,XX +XXX,XX @@ union bpf_attr {
  *		0 on success.
  *
  *		**-ENOENT** if the bpf_local_storage cannot be found.
+ *
+ * void *bpf_mptcp_send_info_to_ssk(void *info)
+ *	Description
+ *		Dynamically cast a *info* pointer to a *sock* pointer.
+ *	Return
+ *		*info* if casting is valid, or **NULL** otherwise.
  */
 #define ___BPF_FUNC_MAPPER(FN, ctx...)			\
 	FN(unspec, 0, ##ctx)				\
@@ -XXX,XX +XXX,XX @@ union bpf_attr {
 	FN(user_ringbuf_drain, 209, ##ctx)		\
 	FN(cgrp_storage_get, 210, ##ctx)		\
 	FN(cgrp_storage_delete, 211, ##ctx)		\
+	FN(mptcp_send_info_to_ssk, 212, ##ctx)		\
 	/* */
 
 /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

Drop this patch. bpf_mptcp_subflow_ctx_by_pos and
mptcp_sched_data_set_contexts are uesless now.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/bpf.c      |  8 --------
 net/mptcp/protocol.h |  2 --
 net/mptcp/sched.c    | 22 ----------------------
 3 files changed, 32 deletions(-)

diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -XXX,XX +XXX,XX @@ __bpf_kfunc static void bpf_mptcp_sock_release(struct mptcp_sock *msk)
 	WARN_ON_ONCE(!sk || !refcount_dec_not_one(&sk->sk_refcnt));
 }
 
-__bpf_kfunc struct mptcp_subflow_context *
-bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos)
-{
-	if (pos >= MPTCP_SUBFLOWS_MAX)
-		return NULL;
-	return data->contexts[pos];
-}
-
 __bpf_kfunc static bool bpf_mptcp_subflow_queues_empty(struct sock *sk)
 {
 	return tcp_rtx_queue_empty(sk);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -XXX,XX +XXX,XX @@ void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
 void mptcp_sock_graft(struct sock *sk, struct socket *parent);
 u64 mptcp_wnd_end(const struct mptcp_sock *msk);
 void mptcp_set_timeout(struct sock *sk);
-struct mptcp_subflow_context *
-bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos);
 struct sock *__mptcp_nmpc_sk(struct mptcp_sock *msk);
 bool __mptcp_close(struct sock *sk, long timeout);
 void mptcp_cancel_work(struct sock *sk);
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -XXX,XX +XXX,XX @@ void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 	WRITE_ONCE(subflow->scheduled, scheduled);
 }
 
-static void mptcp_sched_data_set_contexts(const struct mptcp_sock *msk,
-					  struct mptcp_sched_data *data)
-{
-	struct mptcp_subflow_context *subflow;
-	int i = 0;
-
-	mptcp_for_each_subflow(msk, subflow) {
-		if (i == MPTCP_SUBFLOWS_MAX) {
-			pr_warn_once("too many subflows");
-			break;
-		}
-		mptcp_subflow_set_scheduled(subflow, false);
-		data->contexts[i++] = subflow;
-	}
-	data->subflows = i;
-
-	for (; i < MPTCP_SUBFLOWS_MAX; i++)
-		data->contexts[i] = NULL;
-}
-
 int mptcp_sched_get_send(struct mptcp_sock *msk)
 {
 	struct mptcp_subflow_context *subflow;
@@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_send(struct mptcp_sock *msk)
 
 	if (msk->sched == &mptcp_sched_default || !msk->sched)
 		return mptcp_sched_default_get_send(msk, &data);
-	mptcp_sched_data_set_contexts(msk, &data);
 	return msk->sched->get_send(msk, &data);
 }
 
@@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_retrans(struct mptcp_sock *msk)
 
 	if (msk->sched == &mptcp_sched_default || !msk->sched)
 		return mptcp_sched_default_get_retrans(msk, &data);
-	mptcp_sched_data_set_contexts(msk, &data);
 	if (!msk->sched->get_retrans)
 		return msk->sched->get_send(msk, &data);
 	return msk->sched->get_retrans(msk, &data);
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

The mptcp_subflow bpf_iter is added now, it's better to use the helper
bpf_for_each(mptcp_subflow) to traverse all subflows on the conn_list of
an MPTCP socket and then call kfunc to modify the fields of each subflow
in the WIP MPTCP BPF packet scheduler examples, instead of converting them
to a fixed array. With this helper, we can get rid of this subflow array
"contexts" and the size of it "subflows" in struct mptcp_sched_data. Then
the entire struct mptcp_sched_data can be dropped.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h | 13 ++-----------
 net/mptcp/sched.c   | 18 +++++++-----------
 2 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -XXX,XX +XXX,XX @@ struct mptcp_out_options {
 #define MPTCP_SCHED_MAX		128
 #define MPTCP_SCHED_BUF_MAX	(MPTCP_SCHED_NAME_MAX * MPTCP_SCHED_MAX)
 
-#define MPTCP_SUBFLOWS_MAX	8
-
-struct mptcp_sched_data {
-	u8	subflows;
-	struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
-};
-
 struct mptcp_sched_ops {
-	int (*get_send)(struct mptcp_sock *msk,
-			struct mptcp_sched_data *data);
-	int (*get_retrans)(struct mptcp_sock *msk,
-			   struct mptcp_sched_data *data);
+	int (*get_send)(struct mptcp_sock *msk);
+	int (*get_retrans)(struct mptcp_sock *msk);
 
 	char			name[MPTCP_SCHED_NAME_MAX];
 	struct module		*owner;
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -XXX,XX +XXX,XX @@
 static DEFINE_SPINLOCK(mptcp_sched_list_lock);
 static LIST_HEAD(mptcp_sched_list);
 
-static int mptcp_sched_default_get_send(struct mptcp_sock *msk,
-					struct mptcp_sched_data *data)
+static int mptcp_sched_default_get_send(struct mptcp_sock *msk)
 {
 	struct sock *ssk;
 
@@ -XXX,XX +XXX,XX @@ static int mptcp_sched_default_get_send(struct mptcp_sock *msk,
 	return 0;
 }
 
-static int mptcp_sched_default_get_retrans(struct mptcp_sock *msk,
-					   struct mptcp_sched_data *data)
+static int mptcp_sched_default_get_retrans(struct mptcp_sock *msk)
 {
 	struct sock *ssk;
 
@@ -XXX,XX +XXX,XX @@ void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 int mptcp_sched_get_send(struct mptcp_sock *msk)
 {
 	struct mptcp_subflow_context *subflow;
-	struct mptcp_sched_data data;
 
 	msk_owned_by_me(msk);
 
@@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_send(struct mptcp_sock *msk)
 	}
 
 	if (msk->sched == &mptcp_sched_default || !msk->sched)
-		return mptcp_sched_default_get_send(msk, &data);
-	return msk->sched->get_send(msk, &data);
+		return mptcp_sched_default_get_send(msk);
+	return msk->sched->get_send(msk);
 }
 
 int mptcp_sched_get_retrans(struct mptcp_sock *msk)
 {
 	struct mptcp_subflow_context *subflow;
-	struct mptcp_sched_data data;
 
 	msk_owned_by_me(msk);
 
@@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_retrans(struct mptcp_sock *msk)
 	}
 
 	if (msk->sched == &mptcp_sched_default || !msk->sched)
-		return mptcp_sched_default_get_retrans(msk, &data);
+		return mptcp_sched_default_get_retrans(msk);
 	if (!msk->sched->get_retrans)
-		return msk->sched->get_send(msk, &data);
-	return msk->sched->get_retrans(msk, &data);
+		return msk->sched->get_send(msk);
+	return msk->sched->get_retrans(msk);
 }
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

Remove bpf_mptcp_subflow_ctx_by_pos from BPF kfunc set.
Drop bpf_mptcp_sched_kfunc_set, use bpf_mptcp_common_kfunc_set instead.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/bpf.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -XXX,XX +XXX,XX @@ __bpf_kfunc static void bpf_mptcp_sock_release(struct mptcp_sock *msk)
 	WARN_ON_ONCE(!sk || !refcount_dec_not_one(&sk->sk_refcnt));
 }
 
+__bpf_kfunc static struct sock *
+bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
+{
+	if (!subflow)
+		return NULL;
+
+	return mptcp_subflow_tcp_sock(subflow);
+}
+
 __bpf_kfunc static bool bpf_mptcp_subflow_queues_empty(struct sock *sk)
 {
 	return tcp_rtx_queue_empty(sk);
@@ -XXX,XX +XXX,XX @@ 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)
 BTF_ID_FLAGS(func, bpf_mptcp_sock_acquire, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_mptcp_sock_release, KF_RELEASE)
-BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids)
-
-static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set = {
-	.owner	= THIS_MODULE,
-	.set	= &bpf_mptcp_common_kfunc_ids,
-};
-
-BTF_KFUNCS_START(bpf_mptcp_sched_kfunc_ids)
 BTF_ID_FLAGS(func, mptcp_subflow_set_scheduled)
-BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx_by_pos)
 BTF_ID_FLAGS(func, mptcp_subflow_active)
 BTF_ID_FLAGS(func, mptcp_set_timeout)
 BTF_ID_FLAGS(func, mptcp_wnd_end)
 BTF_ID_FLAGS(func, tcp_stream_memory_free)
 BTF_ID_FLAGS(func, bpf_mptcp_subflow_queues_empty)
+BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock, KF_RET_NULL)
 BTF_ID_FLAGS(func, mptcp_pm_subflow_chk_stale, KF_SLEEPABLE)
-BTF_KFUNCS_END(bpf_mptcp_sched_kfunc_ids)
+BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids)
 
-static const struct btf_kfunc_id_set bpf_mptcp_sched_kfunc_set = {
+static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set = {
 	.owner	= THIS_MODULE,
-	.set	= &bpf_mptcp_sched_kfunc_ids,
+	.set	= &bpf_mptcp_common_kfunc_ids,
 };
 
 static int __init bpf_mptcp_kfunc_init(void)
@@ -XXX,XX +XXX,XX @@ static int __init bpf_mptcp_kfunc_init(void)
 	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);
+					       &bpf_mptcp_common_kfunc_set);
 #ifdef CONFIG_BPF_JIT
 	ret = ret ?: register_bpf_struct_ops(&bpf_mptcp_sched_ops, mptcp_sched_ops);
 #endif
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.

Drop bpf_mptcp_subflow_ctx_by_pos declaration.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/bpf/progs/mptcp_bpf.h       |  3 ---
 tools/testing/selftests/bpf/progs/mptcp_bpf_first.c | 11 ++++++++---
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf.h b/tools/testing/selftests/bpf/progs/mptcp_bpf.h
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf.h
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf.h
@@ -XXX,XX +XXX,XX @@ bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow) __ksym;
 extern void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 					bool scheduled) __ksym;
 
-extern struct mptcp_subflow_context *
-bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos) __ksym;
-
 #endif
diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_first_release, struct mptcp_sock *msk)
 }
 
 SEC("struct_ops")
-int BPF_PROG(bpf_first_get_send, struct mptcp_sock *msk,
-	     struct mptcp_sched_data *data)
+int BPF_PROG(bpf_first_get_send, struct mptcp_sock *msk)
 {
-	mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, 0), true);
+	struct mptcp_subflow_context *subflow;
+
+	subflow = bpf_mptcp_subflow_ctx(msk->first);
+	if (!subflow)
+		return -1;
+
+	mptcp_subflow_set_scheduled(subflow, true);
 	return 0;
 }
 
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 .../selftests/bpf/progs/mptcp_bpf_bkup.c      | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_bkup_release, struct mptcp_sock *msk)
 }
 
 SEC("struct_ops")
-int BPF_PROG(bpf_bkup_get_send, struct mptcp_sock *msk,
-	     struct mptcp_sched_data *data)
+int BPF_PROG(bpf_bkup_get_send, struct mptcp_sock *msk)
 {
-	int nr = -1;
-
-	for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		struct mptcp_subflow_context *subflow;
-
-		subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
-		if (!subflow)
-			break;
+	struct mptcp_subflow_context *subflow;
 
+	bpf_for_each(mptcp_subflow, subflow, msk) {
 		if (!BPF_CORE_READ_BITFIELD_PROBED(subflow, backup) ||
 		    !BPF_CORE_READ_BITFIELD_PROBED(subflow, request_bkup)) {
-			nr = i;
+			mptcp_subflow_set_scheduled(subflow, true);
 			break;
 		}
 	}
 
-	if (nr != -1) {
-		mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, nr), true);
-		return -1;
-	}
 	return 0;
 }
 
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 .../selftests/bpf/progs/mptcp_bpf_rr.c        | 34 ++++++++-----------
 1 file changed, 15 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_rr_release, struct mptcp_sock *msk)
 }
 
 SEC("struct_ops")
-int BPF_PROG(bpf_rr_get_send, struct mptcp_sock *msk,
-	     struct mptcp_sched_data *data)
+int BPF_PROG(bpf_rr_get_send, struct mptcp_sock *msk)
 {
-	struct mptcp_subflow_context *subflow;
+	struct mptcp_subflow_context *subflow, *next;
 	struct mptcp_rr_storage *ptr;
-	struct sock *last_snd = NULL;
-	int nr = 0;
 
 	ptr = bpf_sk_storage_get(&mptcp_rr_map, msk, 0,
 				 BPF_LOCAL_STORAGE_GET_F_CREATE);
 	if (!ptr)
 		return -1;
 
-	last_snd = ptr->last_snd;
+	next = bpf_mptcp_subflow_ctx(msk->first);
+	if (!next)
+		return -1;
 
-	for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
-		if (!last_snd || !subflow)
-			break;
+	if (!ptr->last_snd)
+		goto out;
 
-		if (mptcp_subflow_tcp_sock(subflow) == last_snd) {
-			if (i + 1 == MPTCP_SUBFLOWS_MAX ||
-			    !bpf_mptcp_subflow_ctx_by_pos(data, i + 1))
+	bpf_for_each(mptcp_subflow, subflow, msk) {
+		if (mptcp_subflow_tcp_sock(subflow) == ptr->last_snd) {
+			subflow = bpf_iter_mptcp_subflow_next(&___it);
+			if (!subflow)
 				break;
 
-			nr = i + 1;
+			next = subflow;
 			break;
 		}
 	}
 
-	subflow = bpf_mptcp_subflow_ctx_by_pos(data, nr);
-	if (!subflow)
-		return -1;
-	mptcp_subflow_set_scheduled(subflow, true);
-	ptr->last_snd = mptcp_subflow_tcp_sock(subflow);
+out:
+	mptcp_subflow_set_scheduled(next, true);
+	ptr->last_snd = mptcp_subflow_tcp_sock(next);
 	return 0;
 }
 
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/bpf/progs/mptcp_bpf_red.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_red_release, struct mptcp_sock *msk)
 }
 
 SEC("struct_ops")
-int BPF_PROG(bpf_red_get_send, struct mptcp_sock *msk,
-	     struct mptcp_sched_data *data)
+int BPF_PROG(bpf_red_get_send, struct mptcp_sock *msk)
 {
-	for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		if (!bpf_mptcp_subflow_ctx_by_pos(data, i))
-			break;
+	struct mptcp_subflow_context *subflow;
 
-		mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, i), true);
-	}
+	bpf_for_each(mptcp_subflow, subflow, msk)
+		mptcp_subflow_set_scheduled(subflow, true);
 
 	return 0;
 }
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.

Use bpf_mptcp_send_info_to_ssk() helper.

Drop bpf_subflow_send_info, use subflow_send_info instead.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 .../selftests/bpf/progs/mptcp_bpf_burst.c     | 68 +++++++------------
 1 file changed, 26 insertions(+), 42 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
@@ -XXX,XX +XXX,XX @@ char _license[] SEC("license") = "GPL";
 
 #define min(a, b) ((a) < (b) ? (a) : (b))
 
-struct bpf_subflow_send_info {
-	__u8 subflow_id;
-	__u64 linger_time;
-};
-
 extern bool mptcp_subflow_active(struct mptcp_subflow_context *subflow) __ksym;
 extern void mptcp_set_timeout(struct sock *sk) __ksym;
 extern __u64 mptcp_wnd_end(const struct mptcp_sock *msk) __ksym;
@@ -XXX,XX +XXX,XX @@ void BPF_PROG(mptcp_sched_burst_release, struct mptcp_sock *msk)
 }
 
 SEC("struct_ops")
-int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
-	     struct mptcp_sched_data *data)
+int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk)
 {
-	struct bpf_subflow_send_info send_info[SSK_MODE_MAX];
+	struct subflow_send_info send_info[SSK_MODE_MAX];
 	struct mptcp_subflow_context *subflow;
 	struct sock *sk = (struct sock *)msk;
 	__u32 pace, burst, wmem;
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 
 	/* pick the subflow with the lower wmem/wspace ratio */
 	for (i = 0; i < SSK_MODE_MAX; ++i) {
-		send_info[i].subflow_id = MPTCP_SUBFLOWS_MAX;
+		send_info[i].ssk = NULL;
 		send_info[i].linger_time = -1;
 	}
 
-	for (i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		bool backup;
-
-		subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
-		if (!subflow)
-			break;
-
-		backup = subflow->backup || subflow->request_bkup;
+	bpf_for_each(mptcp_subflow, subflow, msk) {
+		bool backup = subflow->backup || subflow->request_bkup;
 
 		ssk = mptcp_subflow_tcp_sock(subflow);
 		if (!mptcp_subflow_active(subflow))
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 
 		linger_time = div_u64((__u64)ssk->sk_wmem_queued << 32, pace);
 		if (linger_time < send_info[backup].linger_time) {
-			send_info[backup].subflow_id = i;
+			send_info[backup].ssk = ssk;
 			send_info[backup].linger_time = linger_time;
 		}
 	}
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 
 	/* pick the best backup if no other subflow is active */
 	if (!nr_active)
-		send_info[SSK_MODE_ACTIVE].subflow_id = send_info[SSK_MODE_BACKUP].subflow_id;
+		send_info[SSK_MODE_ACTIVE].ssk = send_info[SSK_MODE_BACKUP].ssk;
 
-	subflow = bpf_mptcp_subflow_ctx_by_pos(data, send_info[SSK_MODE_ACTIVE].subflow_id);
-	if (!subflow)
-		return -1;
-	ssk = mptcp_subflow_tcp_sock(subflow);
+	ssk = bpf_mptcp_send_info_to_ssk(&send_info[SSK_MODE_ACTIVE]);
 	if (!ssk || !sk_stream_memory_free(ssk))
 		return -1;
 
+	subflow = bpf_mptcp_subflow_ctx(ssk);
+	if (!subflow)
+		return -1;
+
 	burst = min(MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt);
 	wmem = ssk->sk_wmem_queued;
 	if (!burst)
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 }
 
 SEC("struct_ops")
-int BPF_PROG(bpf_burst_get_retrans, struct mptcp_sock *msk,
-	     struct mptcp_sched_data *data)
+int BPF_PROG(bpf_burst_get_retrans, struct mptcp_sock *msk)
 {
-	int backup = MPTCP_SUBFLOWS_MAX, pick = MPTCP_SUBFLOWS_MAX, subflow_id;
+	struct sock *backup = NULL, *pick = NULL;
 	struct mptcp_subflow_context *subflow;
 	int min_stale_count = INT_MAX;
-	struct sock *ssk;
 
-	for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
-		if (!subflow)
-			break;
+	bpf_for_each(mptcp_subflow, subflow, msk) {
+		struct sock *ssk = bpf_mptcp_subflow_tcp_sock(subflow);
 
-		if (!mptcp_subflow_active(subflow))
+		if (!ssk || !mptcp_subflow_active(subflow))
 			continue;
 
-		ssk = mptcp_subflow_tcp_sock(subflow);
 		/* still data outstanding at TCP level? skip this */
 		if (!tcp_rtx_and_write_queues_empty(ssk)) {
 			mptcp_pm_subflow_chk_stale(msk, ssk);
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_retrans, struct mptcp_sock *msk,
 		}
 
 		if (subflow->backup || subflow->request_bkup) {
-			if (backup == MPTCP_SUBFLOWS_MAX)
-				backup = i;
+			if (!backup)
+				backup = ssk;
 			continue;
 		}
 
-		if (pick == MPTCP_SUBFLOWS_MAX)
-			pick = i;
+		if (!pick)
+			pick = ssk;
 	}
 
-	if (pick < MPTCP_SUBFLOWS_MAX) {
-		subflow_id = pick;
+	if (pick)
 		goto out;
-	}
-	subflow_id = min_stale_count > 1 ? backup : MPTCP_SUBFLOWS_MAX;
+	pick = min_stale_count > 1 ? backup : NULL;
 
 out:
-	subflow = bpf_mptcp_subflow_ctx_by_pos(data, subflow_id);
+	if (!pick)
+		return -1;
+	subflow = bpf_mptcp_subflow_ctx(pick);
 	if (!subflow)
 		return -1;
 	mptcp_subflow_set_scheduled(subflow, true);
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

v13:
 - use '__ign' suffix to ignore the argument type checks of
   bpf_mptcp_subflow_ctx() and bpf_sk_stream_memory_free(),
   instead of adding a new helper bpf_mptcp_send_info_to_ssk().
 - use 'bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk)' instead
   of using 'bpf_for_each(mptcp_subflow, subflow, msk)'.
 - keep struct mptcp_sched_data for future use.

Depends on:
 - Squash to "Add mptcp_subflow bpf_iter support", v2

Based-on: <cover.1738470660.git.tanggeliang@kylinos.cn>

v12:
 - drop struct mptcp_sched_data.
 - rebased on "split get_subflow interface into two" v2.

v10:
 - drop mptcp_subflow_set_scheduled() helper and WRITE_ONCE() in BPF.
 - add new bpf helper bpf_mptcp_send_info_to_ssk() for burst scheduler.

v9:
 - merge 'Fixes for "use bpf_iter in bpf schedulers" v8' into this set.
 - rebased on "add netns helpers" v4

v7:
 - move cleanup patches out of this set.
 - rebased.

v6:
 - rebased to "add mptcp_subflow bpf_iter" v10

v4:
 - patch 2, a new cleanup for "bpf: Add bpf_mptcp_sched_ops".
 - patch 3 should be reverted.
 - patch 8, register kfunc_set.

v3:
 - rebased.
 - put the "drop has_bytes_sent" squash-to patch into this set.

v2:
 - update bpf_rr and bpf_burst

bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk) {
                ... ...
                mptcp_subflow_set_scheduled(subflow, true);
        }

Geliang Tang (9):
  Squash to "bpf: Register mptcp common kfunc set"
  Revert "mptcp: add sched_data helpers"
  Squash to "bpf: Export mptcp packet scheduler helpers"
  Squash to "selftests/bpf: Add bpf_first scheduler & test"
  Squash to "selftests/bpf: Add bpf_bkup scheduler & test"
  Squash to "selftests/bpf: Add bpf_rr scheduler & test"
  Squash to "selftests/bpf: Add bpf_red scheduler & test"
  Squash to "selftests/bpf: Add bpf_burst scheduler & test"
  mptcp: drop subflow contexts in mptcp_sched_data

include/net/mptcp.h                           |  3 -
 net/mptcp/bpf.c                               | 52 +++++++------
 net/mptcp/protocol.h                          |  2 -
 net/mptcp/sched.c                             | 22 ------
 tools/testing/selftests/bpf/progs/mptcp_bpf.h |  3 -
 .../selftests/bpf/progs/mptcp_bpf_bkup.c      | 16 +---
 .../selftests/bpf/progs/mptcp_bpf_burst.c     | 78 +++++++------------
 .../selftests/bpf/progs/mptcp_bpf_first.c     |  8 +-
 .../selftests/bpf/progs/mptcp_bpf_red.c       |  8 +-
 .../selftests/bpf/progs/mptcp_bpf_rr.c        | 31 ++++----
 10 files changed, 80 insertions(+), 143 deletions(-)

-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Instead of adding a new BPF function bpf_mptcp_send_info_to_ssk() in
v12, this patch uses a much more simpler approach, which using '__ign'
suffix for the argument of bpf_mptcp_subflow_ctx() to let BPF to
ignore the type check of this argument.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/bpf.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -XXX,XX +XXX,XX @@ struct bpf_iter_mptcp_subflow_kern {
 __bpf_kfunc_start_defs();
 
 __bpf_kfunc static struct mptcp_subflow_context *
-bpf_mptcp_subflow_ctx(const struct sock *sk)
+bpf_mptcp_subflow_ctx(const struct sock *sk__ign)
 {
-	if (sk && sk_fullsock(sk) &&
-	    sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk))
-		return mptcp_subflow_ctx(sk);
+	if (sk__ign && sk_fullsock(sk__ign) &&
+	    sk__ign->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk__ign))
+		return mptcp_subflow_ctx(sk__ign);
 
 	return NULL;
 }
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Drop this patch. bpf_mptcp_subflow_ctx_by_pos and
mptcp_sched_data_set_contexts are uesless now.

diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -XXX,XX +XXX,XX @@ bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subflow *it)
 {
 }
 
-__bpf_kfunc struct mptcp_subflow_context *
-bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos)
-{
-	if (pos >= MPTCP_SUBFLOWS_MAX)
-		return NULL;
-	return data->contexts[pos];
-}
-
 __bpf_kfunc static bool bpf_mptcp_subflow_queues_empty(struct sock *sk)
 {
 	return tcp_rtx_queue_empty(sk);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -XXX,XX +XXX,XX @@ void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
 void mptcp_sock_graft(struct sock *sk, struct socket *parent);
 u64 mptcp_wnd_end(const struct mptcp_sock *msk);
 void mptcp_set_timeout(struct sock *sk);
-struct mptcp_subflow_context *
-bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos);
 struct sock *__mptcp_nmpc_sk(struct mptcp_sock *msk);
 bool __mptcp_close(struct sock *sk, long timeout);
 void mptcp_cancel_work(struct sock *sk);
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -XXX,XX +XXX,XX @@ void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 	WRITE_ONCE(subflow->scheduled, scheduled);
 }
 
-static void mptcp_sched_data_set_contexts(const struct mptcp_sock *msk,
-					  struct mptcp_sched_data *data)
-{
-	struct mptcp_subflow_context *subflow;
-	int i = 0;
-
-	mptcp_for_each_subflow(msk, subflow) {
-		if (i == MPTCP_SUBFLOWS_MAX) {
-			pr_warn_once("too many subflows");
-			break;
-		}
-		mptcp_subflow_set_scheduled(subflow, false);
-		data->contexts[i++] = subflow;
-	}
-	data->subflows = i;
-
-	for (; i < MPTCP_SUBFLOWS_MAX; i++)
-		data->contexts[i] = NULL;
-}
-
 int mptcp_sched_get_send(struct mptcp_sock *msk)
 {
 	struct mptcp_subflow_context *subflow;
@@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_send(struct mptcp_sock *msk)
 
 	if (msk->sched == &mptcp_sched_default || !msk->sched)
 		return mptcp_sched_default_get_send(msk, &data);
-	mptcp_sched_data_set_contexts(msk, &data);
 	return msk->sched->get_send(msk, &data);
 }
 
@@ -XXX,XX +XXX,XX @@ int mptcp_sched_get_retrans(struct mptcp_sock *msk)
 	if (msk->sched == &mptcp_sched_default || !msk->sched)
 		return mptcp_sched_default_get_retrans(msk, &data);
 
-	mptcp_sched_data_set_contexts(msk, &data);
 	if (msk->sched->get_retrans)
 		return msk->sched->get_retrans(msk, &data);
 	return msk->sched->get_send(msk, &data);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Remove bpf_mptcp_subflow_ctx_by_pos from BPF kfunc set.
Drop bpf_mptcp_sched_kfunc_set, use bpf_mptcp_common_kfunc_set instead.
Add new helpers bpf_mptcp_subflow_tcp_sock() and
bpf_sk_stream_memory_free().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/bpf.c | 38 ++++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -XXX,XX +XXX,XX @@ bpf_mptcp_subflow_ctx(const struct sock *sk__ign)
 	return NULL;
 }
 
+__bpf_kfunc static struct sock *
+bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
+{
+	if (!subflow)
+		return NULL;
+
+	return mptcp_subflow_tcp_sock(subflow);
+}
+
 __bpf_kfunc static int
 bpf_iter_mptcp_subflow_new(struct bpf_iter_mptcp_subflow *it,
 			   struct sock *sk)
@@ -XXX,XX +XXX,XX @@ __bpf_kfunc static bool bpf_mptcp_subflow_queues_empty(struct sock *sk)
 	return tcp_rtx_queue_empty(sk);
 }
 
+__bpf_kfunc static bool bpf_sk_stream_memory_free(const struct sock *sk__ign)
+{
+	if (sk__ign && sk_fullsock(sk__ign) &&
+	    sk__ign->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk__ign))
+		return sk_stream_memory_free(sk__ign);
+
+	return NULL;
+}
+
 __bpf_kfunc_end_defs();
 
 BTF_KFUNCS_START(bpf_mptcp_common_kfunc_ids)
 BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx, KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock, 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)
-BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids)
-
-static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set = {
-	.owner	= THIS_MODULE,
-	.set	= &bpf_mptcp_common_kfunc_ids,
-};
-
-BTF_KFUNCS_START(bpf_mptcp_sched_kfunc_ids)
 BTF_ID_FLAGS(func, mptcp_subflow_set_scheduled)
-BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx_by_pos)
 BTF_ID_FLAGS(func, mptcp_subflow_active)
 BTF_ID_FLAGS(func, mptcp_set_timeout)
 BTF_ID_FLAGS(func, mptcp_wnd_end)
-BTF_ID_FLAGS(func, tcp_stream_memory_free)
+BTF_ID_FLAGS(func, bpf_sk_stream_memory_free, KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_mptcp_subflow_queues_empty)
 BTF_ID_FLAGS(func, mptcp_pm_subflow_chk_stale, KF_SLEEPABLE)
-BTF_KFUNCS_END(bpf_mptcp_sched_kfunc_ids)
+BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids)
 
-static const struct btf_kfunc_id_set bpf_mptcp_sched_kfunc_set = {
+static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set = {
 	.owner	= THIS_MODULE,
-	.set	= &bpf_mptcp_sched_kfunc_ids,
+	.set	= &bpf_mptcp_common_kfunc_ids,
 };
 
 static int __init bpf_mptcp_kfunc_init(void)
@@ -XXX,XX +XXX,XX @@ static int __init bpf_mptcp_kfunc_init(void)
 	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);
+					       &bpf_mptcp_common_kfunc_set);
 #ifdef CONFIG_BPF_JIT
 	ret = ret ?: register_bpf_struct_ops(&bpf_mptcp_sched_ops, mptcp_sched_ops);
 #endif
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.
Drop bpf_mptcp_subflow_ctx_by_pos declaration.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/bpf/progs/mptcp_bpf.h       | 3 ---
 tools/testing/selftests/bpf/progs/mptcp_bpf_first.c | 8 +++++++-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf.h b/tools/testing/selftests/bpf/progs/mptcp_bpf.h
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf.h
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf.h
@@ -XXX,XX +XXX,XX @@ bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow) __ksym;
 extern void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 					bool scheduled) __ksym;
 
-extern struct mptcp_subflow_context *
-bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos) __ksym;
-
 #endif
diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
 int BPF_PROG(bpf_first_get_send, struct mptcp_sock *msk,
 	     struct mptcp_sched_data *data)
 {
-	mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, 0), true);
+	struct mptcp_subflow_context *subflow;
+
+	subflow = bpf_mptcp_subflow_ctx(msk->first);
+	if (!subflow)
+		return -1;
+
+	mptcp_subflow_set_scheduled(subflow, true);
 	return 0;
 }
 
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 .../testing/selftests/bpf/progs/mptcp_bpf_bkup.c | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_bkup.c
@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
 int BPF_PROG(bpf_bkup_get_send, struct mptcp_sock *msk,
 	     struct mptcp_sched_data *data)
 {
-	int nr = -1;
-
-	for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		struct mptcp_subflow_context *subflow;
-
-		subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
-		if (!subflow)
-			break;
+	struct mptcp_subflow_context *subflow;
 
+	bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk) {
 		if (!BPF_CORE_READ_BITFIELD_PROBED(subflow, backup) ||
 		    !BPF_CORE_READ_BITFIELD_PROBED(subflow, request_bkup)) {
-			nr = i;
+			mptcp_subflow_set_scheduled(subflow, true);
 			break;
 		}
 	}
 
-	if (nr != -1) {
-		mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, nr), true);
-		return -1;
-	}
 	return 0;
 }
 
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 .../selftests/bpf/progs/mptcp_bpf_rr.c        | 31 +++++++++----------
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
 int BPF_PROG(bpf_rr_get_send, struct mptcp_sock *msk,
 	     struct mptcp_sched_data *data)
 {
-	struct mptcp_subflow_context *subflow;
+	struct mptcp_subflow_context *subflow, *next;
 	struct mptcp_rr_storage *ptr;
-	struct sock *last_snd = NULL;
-	int nr = 0;
 
 	ptr = bpf_sk_storage_get(&mptcp_rr_map, msk, 0,
 				 BPF_LOCAL_STORAGE_GET_F_CREATE);
 	if (!ptr)
 		return -1;
 
-	last_snd = ptr->last_snd;
+	next = bpf_mptcp_subflow_ctx(msk->first);
+	if (!next)
+		return -1;
 
-	for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
-		if (!last_snd || !subflow)
-			break;
+	if (!ptr->last_snd)
+		goto out;
 
-		if (mptcp_subflow_tcp_sock(subflow) == last_snd) {
-			if (i + 1 == MPTCP_SUBFLOWS_MAX ||
-			    !bpf_mptcp_subflow_ctx_by_pos(data, i + 1))
+	bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk) {
+		if (mptcp_subflow_tcp_sock(subflow) == ptr->last_snd) {
+			subflow = bpf_iter_mptcp_subflow_next(&___it);
+			if (!subflow)
 				break;
 
-			nr = i + 1;
+			next = subflow;
 			break;
 		}
 	}
 
-	subflow = bpf_mptcp_subflow_ctx_by_pos(data, nr);
-	if (!subflow)
-		return -1;
-	mptcp_subflow_set_scheduled(subflow, true);
-	ptr->last_snd = mptcp_subflow_tcp_sock(subflow);
+out:
+	mptcp_subflow_set_scheduled(next, true);
+	ptr->last_snd = mptcp_subflow_tcp_sock(next);
 	return 0;
 }
 
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/bpf/progs/mptcp_bpf_red.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
 int BPF_PROG(bpf_red_get_send, struct mptcp_sock *msk,
 	     struct mptcp_sched_data *data)
 {
-	for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		if (!bpf_mptcp_subflow_ctx_by_pos(data, i))
-			break;
+	struct mptcp_subflow_context *subflow;
 
-		mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, i), true);
-	}
+	bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk)
+		mptcp_subflow_set_scheduled(subflow, true);
 
 	return 0;
 }
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Use the newly added bpf_for_each() helper to walk the conn_list.
Drop bpf_subflow_send_info, use subflow_send_info instead.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 .../selftests/bpf/progs/mptcp_bpf_burst.c     | 78 +++++++------------
 1 file changed, 26 insertions(+), 52 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_burst.c
@@ -XXX,XX +XXX,XX @@ char _license[] SEC("license") = "GPL";
 
 #define min(a, b) ((a) < (b) ? (a) : (b))
 
-struct bpf_subflow_send_info {
-	__u8 subflow_id;
-	__u64 linger_time;
-};
-
 extern bool mptcp_subflow_active(struct mptcp_subflow_context *subflow) __ksym;
 extern void mptcp_set_timeout(struct sock *sk) __ksym;
 extern __u64 mptcp_wnd_end(const struct mptcp_sock *msk) __ksym;
-extern bool tcp_stream_memory_free(const struct sock *sk, int wake) __ksym;
+extern bool bpf_sk_stream_memory_free(const struct sock *sk) __ksym;
 extern bool bpf_mptcp_subflow_queues_empty(struct sock *sk) __ksym;
 extern void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk) __ksym;
 
@@ -XXX,XX +XXX,XX @@ static __always_inline bool tcp_rtx_and_write_queues_empty(struct sock *sk)
 	return bpf_mptcp_subflow_queues_empty(sk) && tcp_write_queue_empty(sk);
 }
 
-static __always_inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
-{
-	if (sk->sk_wmem_queued >= sk->sk_sndbuf)
-		return false;
-
-	return tcp_stream_memory_free(sk, wake);
-}
-
-static __always_inline bool sk_stream_memory_free(const struct sock *sk)
-{
-	return __sk_stream_memory_free(sk, 0);
-}
-
 SEC("struct_ops")
 void BPF_PROG(mptcp_sched_burst_init, struct mptcp_sock *msk)
 {
@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
 int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 	     struct mptcp_sched_data *data)
 {
-	struct bpf_subflow_send_info send_info[SSK_MODE_MAX];
+	struct subflow_send_info send_info[SSK_MODE_MAX];
 	struct mptcp_subflow_context *subflow;
 	struct sock *sk = (struct sock *)msk;
 	__u32 pace, burst, wmem;
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 
 	/* pick the subflow with the lower wmem/wspace ratio */
 	for (i = 0; i < SSK_MODE_MAX; ++i) {
-		send_info[i].subflow_id = MPTCP_SUBFLOWS_MAX;
+		send_info[i].ssk = NULL;
 		send_info[i].linger_time = -1;
 	}
 
-	for (i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		bool backup;
-
-		subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
-		if (!subflow)
-			break;
-
-		backup = subflow->backup || subflow->request_bkup;
+	bpf_for_each(mptcp_subflow, subflow, sk) {
+		bool backup = subflow->backup || subflow->request_bkup;
 
 		ssk = mptcp_subflow_tcp_sock(subflow);
 		if (!mptcp_subflow_active(subflow))
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 
 		linger_time = div_u64((__u64)ssk->sk_wmem_queued << 32, pace);
 		if (linger_time < send_info[backup].linger_time) {
-			send_info[backup].subflow_id = i;
+			send_info[backup].ssk = ssk;
 			send_info[backup].linger_time = linger_time;
 		}
 	}
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_send, struct mptcp_sock *msk,
 
 	/* pick the best backup if no other subflow is active */
 	if (!nr_active)
-		send_info[SSK_MODE_ACTIVE].subflow_id = send_info[SSK_MODE_BACKUP].subflow_id;
+		send_info[SSK_MODE_ACTIVE].ssk = send_info[SSK_MODE_BACKUP].ssk;
 
-	subflow = bpf_mptcp_subflow_ctx_by_pos(data, send_info[SSK_MODE_ACTIVE].subflow_id);
-	if (!subflow)
+	ssk = send_info[SSK_MODE_ACTIVE].ssk;
+	if (!ssk || !bpf_sk_stream_memory_free(ssk))
 		return -1;
-	ssk = mptcp_subflow_tcp_sock(subflow);
-	if (!ssk || !sk_stream_memory_free(ssk))
+
+	subflow = bpf_mptcp_subflow_ctx(ssk);
+	if (!subflow)
 		return -1;
 
 	burst = min(MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt);
+	ssk = bpf_core_cast(ssk, struct sock);
 	wmem = ssk->sk_wmem_queued;
 	if (!burst)
 		goto out;
@@ -XXX,XX +XXX,XX @@ SEC("struct_ops")
 int BPF_PROG(bpf_burst_get_retrans, struct mptcp_sock *msk,
 	     struct mptcp_sched_data *data)
 {
-	int backup = MPTCP_SUBFLOWS_MAX, pick = MPTCP_SUBFLOWS_MAX, subflow_id;
+	struct sock *backup = NULL, *pick = NULL;
 	struct mptcp_subflow_context *subflow;
 	int min_stale_count = INT_MAX;
-	struct sock *ssk;
 
-	for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
-		subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
-		if (!subflow)
-			break;
+	bpf_for_each(mptcp_subflow, subflow, (struct sock *)msk) {
+		struct sock *ssk = bpf_mptcp_subflow_tcp_sock(subflow);
 
-		if (!mptcp_subflow_active(subflow))
+		if (!ssk || !mptcp_subflow_active(subflow))
 			continue;
 
-		ssk = mptcp_subflow_tcp_sock(subflow);
 		/* still data outstanding at TCP level? skip this */
 		if (!tcp_rtx_and_write_queues_empty(ssk)) {
 			mptcp_pm_subflow_chk_stale(msk, ssk);
@@ -XXX,XX +XXX,XX @@ int BPF_PROG(bpf_burst_get_retrans, struct mptcp_sock *msk,
 		}
 
 		if (subflow->backup || subflow->request_bkup) {
-			if (backup == MPTCP_SUBFLOWS_MAX)
-				backup = i;
+			if (!backup)
+				backup = ssk;
 			continue;
 		}
 
-		if (pick == MPTCP_SUBFLOWS_MAX)
-			pick = i;
+		if (!pick)
+			pick = ssk;
 	}
 
-	if (pick < MPTCP_SUBFLOWS_MAX) {
-		subflow_id = pick;
+	if (pick)
 		goto out;
-	}
-	subflow_id = min_stale_count > 1 ? backup : MPTCP_SUBFLOWS_MAX;
+	pick = min_stale_count > 1 ? backup : NULL;
 
 out:
-	subflow = bpf_mptcp_subflow_ctx_by_pos(data, subflow_id);
+	if (!pick)
+		return -1;
+	subflow = bpf_mptcp_subflow_ctx(pick);
 	if (!subflow)
 		return -1;
 	mptcp_subflow_set_scheduled(subflow, true);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h | 3 ---
 1 file changed, 3 deletions(-)