Series comparison

-[PATCH mptcp-next v1 0/6] BPF path manager, part 4
+[PATCH mptcp-next v5 0/9] BPF path manager, part 4
 From: Geliang Tang <tanggeliang@kylinos.cn>
-Some path manager related refactoring and cleanups.
+v5:
  - use "struct mptcp_pm_param *param" as unified parameters for all
    interfaces.
  - register in-kernel mptcp_pm_ops too.
  - only implement two interfaces "get_local_id" and "get_priority" in
    this set.
-Geliang Tang (6):
+v4:
-  mptcp: pm: in-kernel: avoid access entry without lock
+ - include a new patch "define BPF path manager type".
-  mptcp: pm: in-kernel: reduce parameters of set_flags
  - add new interfaces:
     created established closed
     listerner_created listener_closed
  - rename interfaces as:
     address_announced address_removed
     subflow_established subflow_closed
     get_priority set_priority
  - rename functions as:
     mptcp_pm_validate
     mptcp_pm_register
     mptcp_pm_unregister
     mptcp_pm_initialize
     mptcp_pm_release
 v3:
  - rename the 2nd parameter of get_local_id() from 'local' to 'skc'.
  - keep the 'msk_sport' check in mptcp_userspace_pm_get_local_id().
  - return 'err' instead of '0' in userspace_pm_subflow_create().
  - drop 'ret' variable inmptcp_pm_data_reset().
  - fix typos in commit log.
 v2:
  - update get_local_id interface in patch 2.
 get_addr() and dump_addr() interfaces of BPF userspace pm are dropped
 as Matt suggested.
 In order to implement BPF path manager, it's necessary to unify the
 interfaces of the path manager. This set contains some cleanups and
 refactoring to unify the interfaces in kernel space. Finally, define
 a struct mptcp_pm_ops for a path manager.
 Geliang Tang (9):
   mptcp: pm: use addr entry for get_local_id
-  mptcp: pm: in-kernel: use kmemdup helper
+  mptcp: pm: add struct mptcp_pm_param
-  sock: add sock_kmemdup helper
+  mptcp: pm: pass pm_param to get_local_id
-  mptcp: pm: userspace: use sock_kmemdup helper
+  mptcp: pm: define struct mptcp_pm_ops
   mptcp: pm: in-kernel: register mptcp_netlink_pm
   mptcp: pm: userspace: register mptcp_userspace_pm
   mptcp: pm: initialize and release mptcp_pm_ops
   mptcp: pm: drop get_local_id helpers
   mptcp: pm: drop is_backup helpers
- include/net/sock.h       |  1 +
+ include/net/mptcp.h      |  42 +++++++++++++
- net/core/sock.c          | 23 +++++++++++++++++++++++
+ net/mptcp/pm.c           | 131 ++++++++++++++++++++++++++++++++++++---
- net/mptcp/pm.c           |  9 ++++++---
+ net/mptcp/pm_netlink.c   |  23 +++++--
- net/mptcp/pm_netlink.c   | 30 +++++++++++++-----------------
+ net/mptcp/pm_userspace.c |  37 ++++++-----
- net/mptcp/pm_userspace.c | 20 +++++++-------------
+ net/mptcp/protocol.c     |   1 +
- net/mptcp/protocol.h     |  6 ++++--
+ net/mptcp/protocol.h     |  24 +++----
-files changed, 54 insertions(+), 35 deletions(-)
+files changed, 216 insertions(+), 42 deletions(-)
 --
 .43.0

-[PATCH mptcp-next v1 3/6] mptcp: pm: use addr entry for get_local_id
+[PATCH mptcp-next v5 1/9] mptcp: pm: use addr entry for get_local_id
 ...
 to mptcp_pm_get_local_id(), and then passing "new_entry" as a parameter to
 both mptcp_pm_nl_get_local_id() and mptcp_userspace_pm_get_local_id().
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- net/mptcp/pm.c           |  9 ++++++---
+ net/mptcp/pm.c           | 11 ++++++++---
- net/mptcp/pm_netlink.c   | 11 ++++-------
+ net/mptcp/pm_netlink.c   |  9 ++++-----
  net/mptcp/pm_userspace.c | 17 ++++++-----------
  net/mptcp/protocol.h     |  6 ++++--
-files changed, 20 insertions(+), 23 deletions(-)
+files changed, 22 insertions(+), 21 deletions(-)
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
 @@ -XXX,XX +XXX,XX @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
  int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
  {
 -    struct mptcp_addr_info skc_local;
-+    struct mptcp_pm_addr_entry skc_local = { 0 };
++    struct mptcp_pm_addr_entry skc_local;
      struct mptcp_addr_info msk_local;
      if (WARN_ON_ONCE(!msk))
-@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
+         return -1;
 +    memset(&skc_local, 0, sizeof(struct mptcp_pm_addr_entry));
 +
      /* The 0 ID mapping is defined by the first subflow, copied into the msk
       * addr
       */
      mptcp_local_address((struct sock_common *)msk, &msk_local);
 -    mptcp_local_address((struct sock_common *)skc, &skc_local);
 -    if (mptcp_addresses_equal(&msk_local, &skc_local, false))
 ...
 -    entry->addr = *skc;
 -    entry->addr.id = 0;
 +    *entry = *skc;
      entry->addr.port = 0;
--    entry->ifindex = 0;
+     entry->ifindex = 0;
 -    entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
--    entry->lsk = NULL;
+     entry->lsk = NULL;
      ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
      if (ret < 0)
-         kfree(entry);
 diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_userspace.c
 +++ b/net/mptcp/pm_userspace.c
 @@ -XXX,XX +XXX,XX @@ mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
 ...

-New patch
+[PATCH mptcp-next v5 2/9] mptcp: pm: add struct mptcp_pm_param
+From: Geliang Tang <tanggeliang@kylinos.cn>
+Generally, in the path manager interfaces, the local address is defined
+as an mptcp_pm_addr_entry type address, while the remote address is
+defined as an mptcp_addr_info type one:
+    (struct mptcp_pm_addr_entry *local, struct mptcp_addr_info *remote)
+In order to make these interfaces more flexible and extensible, a struct
+mptcp_pm_param is defined here to pass parameters. "entry" can be used
+as the local address entry, and "addr" can be used as the remote address.
+Also add a new helper mptcp_pm_param_set_contexts() to set a struct
+mptcp_pm_param type parameter.
+Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
+---
+ include/net/mptcp.h  | 13 +++++++++++++
+ net/mptcp/pm.c       | 10 ++++++++++
+ net/mptcp/protocol.h | 11 +++--------
+files changed, 26 insertions(+), 8 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_sched_ops {
+     void (*release)(struct mptcp_sock *msk);
+ } ____cacheline_aligned_in_smp;
++struct mptcp_pm_addr_entry {
++    struct list_head    list;
++    struct mptcp_addr_info    addr;
++    u8            flags;
++    int            ifindex;
++    struct socket        *lsk;
++};
++
++struct mptcp_pm_param {
++    struct mptcp_pm_addr_entry    entry;
++    struct mptcp_addr_info        addr;
++};
++
+ #ifdef CONFIG_MPTCP
+ void mptcp_init(void);
+diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm.c
++++ b/net/mptcp/pm.c
+@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
+     return ret;
+ }
++void mptcp_pm_param_set_contexts(struct mptcp_pm_param *param,
++                 const struct mptcp_pm_addr_entry *entry,
++                 const struct mptcp_addr_info *addr)
++{
++    if (entry)
++        param->entry = *entry;
++    if (addr)
++        param->addr = *addr;
++}
++
+ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
+ {
+     struct mptcp_pm_addr_entry skc_local;
+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 @@ struct mptcp_pm_local {
+     int            ifindex;
+ };
+-struct mptcp_pm_addr_entry {
+-    struct list_head    list;
+-    struct mptcp_addr_info    addr;
+-    u8            flags;
+-    int            ifindex;
+-    struct socket        *lsk;
+-};
+-
+ struct mptcp_data_frag {
+     struct list_head list;
+     u64 data_seq;
+@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
+                   bool *drop_other_suboptions);
+ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
+                  struct mptcp_rm_list *rm_list);
++void mptcp_pm_param_set_contexts(struct mptcp_pm_param *param,
++                 const struct mptcp_pm_addr_entry *entry,
++                 const struct mptcp_addr_info *addr);
+ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
+ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
+                  struct mptcp_pm_addr_entry *skc);
+--
+.43.0

-[PATCH mptcp-next v1 2/6] mptcp: pm: in-kernel: reduce parameters of set_flags
+[PATCH mptcp-next v5 3/9] mptcp: pm: pass pm_param to get_local_id
 From: Geliang Tang <tanggeliang@kylinos.cn>
-The number of parameters in mptcp_nl_set_flags() can be reduced.
+This patch changes the 2nd parameter of get_local_id() interface as
-Only need to pass a "local" parameter to it instead of "local->addr"
+"struct mptcp_pm_param" type. Only "entry" member of this struct is
-and "local->flags".
+used.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- net/mptcp/pm_netlink.c | 15 ++++++++-------
+ net/mptcp/pm.c           | 6 ++++--
-file changed, 8 insertions(+), 7 deletions(-)
+ net/mptcp/pm_netlink.c   | 3 ++-
  net/mptcp/pm_userspace.c | 3 ++-
  net/mptcp/protocol.h     | 4 ++--
 files changed, 10 insertions(+), 6 deletions(-)
+diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm.c
++++ b/net/mptcp/pm.c
+@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
+ {
+     struct mptcp_pm_addr_entry skc_local;
+     struct mptcp_addr_info msk_local;
++    struct mptcp_pm_param param;
+     if (WARN_ON_ONCE(!msk))
+         return -1;
+@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
+     skc_local.addr.id = 0;
+     skc_local.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
++    mptcp_pm_param_set_contexts(&param, &skc_local, NULL);
+     if (mptcp_pm_is_userspace(msk))
+-        return mptcp_userspace_pm_get_local_id(msk, &skc_local);
+-    return mptcp_pm_nl_get_local_id(msk, &skc_local);
++        return mptcp_userspace_pm_get_local_id(msk, &param);
++    return mptcp_pm_nl_get_local_id(msk, &param);
+ }
+ bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
 diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_netlink.c
 +++ b/net/mptcp/pm_netlink.c
-@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
+@@ -XXX,XX +XXX,XX @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
      spin_unlock_bh(&msk->pm.lock);
  }
--static void mptcp_nl_set_flags(struct net *net, struct mptcp_addr_info *addr,
+ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
--                   u8 flags, u8 changed)
+-                 struct mptcp_pm_addr_entry *skc)
-+static void mptcp_nl_set_flags(struct net *net,
++                 struct mptcp_pm_param *param)
 +                   struct mptcp_pm_addr_entry *local,
 +                   u8 changed)
  {
--    u8 is_subflow = !!(flags & MPTCP_PM_ADDR_FLAG_SUBFLOW);
++    struct mptcp_pm_addr_entry *skc = &param->entry;
--    u8 bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+     struct mptcp_pm_addr_entry *entry;
-+    u8 is_subflow = !!(local->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW);
+     struct pm_nl_pernet *pernet;
-+    u8 bkup = !!(local->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+     int ret;
-     long s_slot = 0, s_num = 0;
+diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
-     struct mptcp_sock *msk;
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm_userspace.c
-@@ -XXX,XX +XXX,XX @@ static void mptcp_nl_set_flags(struct net *net, struct mptcp_addr_info *addr,
++++ b/net/mptcp/pm_userspace.c
+@@ -XXX,XX +XXX,XX @@ mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
          lock_sock(sk);
          if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
 -            mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
 +            mptcp_pm_nl_mp_prio_send_ack(msk, &local->addr, NULL, bkup);
          /* Subflows will only be recreated if the SUBFLOW flag is set */
          if (is_subflow && (changed & MPTCP_PM_ADDR_FLAG_FULLMESH))
 -            mptcp_pm_nl_fullmesh(msk, addr);
 +            mptcp_pm_nl_fullmesh(msk, &local->addr);
          release_sock(sk);
  next:
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
      *local = *entry;
      spin_unlock_bh(&pernet->lock);
 -    mptcp_nl_set_flags(net, &local->addr, local->flags, changed);
 +    mptcp_nl_set_flags(net, local, changed);
      return 0;
  }
+ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
+-                    struct mptcp_pm_addr_entry *skc)
++                    struct mptcp_pm_param *param)
+ {
+     __be16 msk_sport =  ((struct inet_sock *)
+                  inet_sk((struct sock *)msk))->inet_sport;
++    struct mptcp_pm_addr_entry *skc = &param->entry;
+     struct mptcp_pm_addr_entry *entry;
+     spin_lock_bh(&msk->pm.lock);
+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_pm_param_set_contexts(struct mptcp_pm_param *param,
+                  const struct mptcp_addr_info *addr);
+ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
+ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
+-                 struct mptcp_pm_addr_entry *skc);
++                 struct mptcp_pm_param *param);
+ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
+-                    struct mptcp_pm_addr_entry *skc);
++                    struct mptcp_pm_param *param);
+ bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
+ bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+ bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 --
 .43.0

-[PATCH mptcp-next v1 5/6] sock: add sock_kmemdup helper
+[PATCH mptcp-next v5 4/9] mptcp: pm: define struct mptcp_pm_ops
 From: Geliang Tang <tanggeliang@kylinos.cn>
-This patch adds the sock version of kmemdup() helper, named sock_kmemdup(),
+In order to allow users to develop their own BPF-based path manager,
-to duplicate a memory block using the socket's option memory buffer.
+this patch defines a struct ops "mptcp_pm_ops" for a userspace path
 manager, which contains a set of interfaces.
 Add a set of functions to register, unregister, find and validate a
 given struct ops.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- include/net/sock.h |  1 +
+ include/net/mptcp.h  | 29 ++++++++++++++++++++++
- net/core/sock.c    | 23 +++++++++++++++++++++++
+ net/mptcp/pm.c       | 59 ++++++++++++++++++++++++++++++++++++++++++++
-files changed, 24 insertions(+)
+ net/mptcp/protocol.h |  5 ++++
 files changed, 93 insertions(+)
-diff --git a/include/net/sock.h b/include/net/sock.h
+diff --git a/include/net/mptcp.h b/include/net/mptcp.h
 index XXXXXXX..XXXXXXX 100644
---- a/include/net/sock.h
+--- a/include/net/mptcp.h
-+++ b/include/net/sock.h
++++ b/include/net/mptcp.h
-@@ -XXX,XX +XXX,XX @@ static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
+@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_param {
      struct mptcp_addr_info        addr;
  };
 +struct mptcp_pm_ops {
 +    int (*created)(struct mptcp_sock *msk);
 +    int (*established)(struct mptcp_sock *msk);
 +    int (*closed)(struct mptcp_sock *msk);
 +    int (*address_announced)(struct mptcp_sock *msk,
 +                 struct mptcp_pm_param *param);
 +    int (*address_removed)(struct mptcp_sock *msk,
 +                   struct mptcp_pm_param *param);
 +    int (*subflow_established)(struct mptcp_sock *msk,
 +                   struct mptcp_pm_param *param);
 +    int (*subflow_closed)(struct mptcp_sock *msk,
 +                  struct mptcp_pm_param *param);
 +    int (*get_local_id)(struct mptcp_sock *msk,
 +                struct mptcp_pm_param *param);
 +    bool (*get_priority)(struct mptcp_sock *msk,
 +                 struct mptcp_pm_param *param);
 +    int (*set_priority)(struct mptcp_sock *msk,
 +                struct mptcp_pm_param *param);
 +    int (*listener_created)(struct mptcp_sock *msk);
 +    int (*listener_closed)(struct mptcp_sock *msk);
 +
 +    u8            type;
 +    struct module        *owner;
 +    struct list_head    list;
 +
 +    void (*init)(struct mptcp_sock *msk);
 +    void (*release)(struct mptcp_sock *msk);
 +} ____cacheline_aligned_in_smp;
 +
  #ifdef CONFIG_MPTCP
  void mptcp_init(void);
 diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm.c
 +++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@
  #define pr_fmt(fmt) "MPTCP: " fmt
  #include <linux/kernel.h>
 +#include <linux/rculist.h>
 +#include <linux/spinlock.h>
  #include <net/mptcp.h>
  #include "protocol.h"
  #include "mib.h"
  #include "mptcp_pm_gen.h"
 +static DEFINE_SPINLOCK(mptcp_pm_list_lock);
 +static LIST_HEAD(mptcp_pm_list);
 +
  /* path manager command handlers */
  int mptcp_pm_announce_addr(struct mptcp_sock *msk,
@@ -XXX,XX +XXX,XX @@ void __init mptcp_pm_init(void)
  {
      mptcp_pm_nl_init();
  }
++
- void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
++/* Must be called with rcu read lock held */
-+void *sock_kmemdup(struct sock *sk, const void *src, int size, gfp_t priority);
++struct mptcp_pm_ops *mptcp_pm_find(enum mptcp_pm_type type)
  void sock_kfree_s(struct sock *sk, void *mem, int size);
  void sock_kzfree_s(struct sock *sk, void *mem, int size);
  void sk_send_sigurg(struct sock *sk);
 diff --git a/net/core/sock.c b/net/core/sock.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/core/sock.c
 +++ b/net/core/sock.c
@@ -XXX,XX +XXX,XX @@ void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
  }
  EXPORT_SYMBOL(sock_kmalloc);
 +/*
 + * Duplicate a memory block using the socket's option memory buffer.
 + */
 +void *sock_kmemdup(struct sock *sk, const void *src, int size, gfp_t priority)
 +{
-+    int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
++    struct mptcp_pm_ops *pm;
 +
-+    if ((unsigned int)size <= optmem_max &&
++    list_for_each_entry_rcu(pm, &mptcp_pm_list, list) {
-+        atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
++        if (pm->type == type)
-+        void *mem;
++            return pm;
 +        /* First do the add, to avoid the race if kmalloc
 +         * might sleep.
 +         */
 +        atomic_add(size, &sk->sk_omem_alloc);
 +        mem = kmemdup(src, size, priority);
 +        if (mem)
 +            return mem;
 +        atomic_sub(size, &sk->sk_omem_alloc);
 +    }
++
 +    return NULL;
 +}
-+EXPORT_SYMBOL(sock_kmemdup);
 +
- /* Free an option memory block. Note, we actually want the inline
++int mptcp_pm_validate(struct mptcp_pm_ops *pm)
-  * here as this allows gcc to detect the nullify and fold away the
++{
-  * condition entirely.
++    if (!pm->created && !pm->established && !pm->closed &&
 +        !pm->address_announced && !pm->address_removed &&
 +        !pm->subflow_established && !pm->subflow_closed &&
 +        !pm->get_local_id && !pm->get_priority && !pm->set_priority &&
 +        !pm->listener_created && !pm->listener_closed) {
 +        pr_err("%u does not implement required ops\n", pm->type);
 +        return -EINVAL;
 +    }
 +
 +    return 0;
 +}
 +
 +int mptcp_pm_register(struct mptcp_pm_ops *pm)
 +{
 +    int ret;
 +
 +    ret = mptcp_pm_validate(pm);
 +    if (ret)
 +        return ret;
 +
 +    spin_lock(&mptcp_pm_list_lock);
 +    if (mptcp_pm_find(pm->type)) {
 +        spin_unlock(&mptcp_pm_list_lock);
 +        return -EEXIST;
 +    }
 +    list_add_tail_rcu(&pm->list, &mptcp_pm_list);
 +    spin_unlock(&mptcp_pm_list_lock);
 +
 +    pr_debug("userspace_pm type %u registered\n", pm->type);
 +    return 0;
 +}
 +
 +void mptcp_pm_unregister(struct mptcp_pm_ops *pm)
 +{
 +    spin_lock(&mptcp_pm_list_lock);
 +    list_del_rcu(&pm->list);
 +    spin_unlock(&mptcp_pm_list_lock);
 +}
 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 @@ int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_
  void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
                  struct mptcp_pm_addr_entry *entry);
 +struct mptcp_pm_ops *mptcp_pm_find(enum mptcp_pm_type type);
 +int mptcp_pm_validate(struct mptcp_pm_ops *pm);
 +int mptcp_pm_register(struct mptcp_pm_ops *pm);
 +void mptcp_pm_unregister(struct mptcp_pm_ops *pm);
 +
  void mptcp_free_local_addr_list(struct mptcp_sock *msk);
  void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
 --
 .43.0

-[PATCH mptcp-next v1 4/6] mptcp: pm: in-kernel: use kmemdup helper
+[PATCH mptcp-next v5 5/9] mptcp: pm: in-kernel: register mptcp_netlink_pm
 From: Geliang Tang <tanggeliang@kylinos.cn>
-Instead of using kmalloc() or kzalloc() to allocate an entry and
+This patch defines the original in-kernel netlink path manager as a new
-then immediately duplicate another entry to the newly allocated
+struct mptcp_pm_ops named "mptcp_netlink_pm", and register it in
-one, kmemdup() helper can be used to simplify the code.
+mptcp_pm_nl_init().
 Only get_local_id() and get_priority() interfaces are implemented here.
 mptcp_pm_nl_is_backup() becomes a wrapper of get_priority().
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- net/mptcp/pm_netlink.c | 6 ++----
+ net/mptcp/pm_netlink.c | 21 ++++++++++++++++++++-
-file changed, 2 insertions(+), 4 deletions(-)
+file changed, 20 insertions(+), 1 deletion(-)
 diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_netlink.c
 +++ b/net/mptcp/pm_netlink.c
 @@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
-         return ret;
+     return ret;
+ }
-     /* address not found, add to local list */
--    entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+-bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
-+    entry = kmemdup(skc, sizeof(*skc), GFP_ATOMIC);
++static bool mptcp_pm_nl_get_priority(struct mptcp_sock *msk,
-     if (!entry)
++                     struct mptcp_pm_param *param)
-         return -ENOMEM;
+ {
+     struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
--    *entry = *skc;
++    struct mptcp_addr_info *skc = &param->addr;
-     entry->addr.port = 0;
+     struct mptcp_pm_addr_entry *entry;
-     ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
+     bool backup;
-     if (ret < 0)
-@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info)
+@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
-         return -EINVAL;
+     return backup;
-     }
+ }
--    entry = kzalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
++bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
-+    entry = kmemdup(&addr, sizeof(addr), GFP_KERNEL_ACCOUNT);
++{
-     if (!entry) {
++    struct mptcp_pm_param param;
-         GENL_SET_ERR_MSG(info, "can't allocate addr");
++
-         return -ENOMEM;
++    mptcp_pm_param_set_contexts(&param, NULL, skc);
-     }
++    return mptcp_pm_nl_get_priority(msk, &param);
++}
--    *entry = addr;
++
-     if (entry->addr.port) {
+ #define MPTCP_PM_CMD_GRP_OFFSET       0
-         ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
+ #define MPTCP_PM_EV_GRP_OFFSET        1
-         if (ret) {
@@ -XXX,XX +XXX,XX @@ static struct pernet_operations mptcp_pm_pernet_ops = {
      .size = sizeof(struct pm_nl_pernet),
  };
 +static struct mptcp_pm_ops mptcp_netlink_pm = {
 +    .get_local_id        = mptcp_pm_nl_get_local_id,
 +    .get_priority        = mptcp_pm_nl_get_priority,
 +    .type            = MPTCP_PM_TYPE_KERNEL,
 +    .owner            = THIS_MODULE,
 +};
 +
  void __init mptcp_pm_nl_init(void)
  {
      if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
@@ -XXX,XX +XXX,XX @@ void __init mptcp_pm_nl_init(void)
      if (genl_register_family(&mptcp_genl_family))
          panic("Failed to register MPTCP PM netlink family\n");
 +
 +    mptcp_pm_register(&mptcp_netlink_pm);
  }
 --
 .43.0

-New patch
+[PATCH mptcp-next v5 6/9] mptcp: pm: userspace: register mptcp_userspace_pm
+From: Geliang Tang <tanggeliang@kylinos.cn>
+This patch defines the original userspace path manager as a new struct
+mptcp_pm_ops named "mptcp_userspace_pm", and register it in
+mptcp_pm_data_init().
+Only get_local_id() and get_priority() interfaces are implemented here.
+mptcp_userspace_pm_is_backup() becomes a wrapper of get_priority().
+Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
+---
+ net/mptcp/pm.c           |  1 +
+ net/mptcp/pm_userspace.c | 26 ++++++++++++++++++++++++--
+ net/mptcp/protocol.h     |  1 +
+files changed, 26 insertions(+), 2 deletions(-)
+diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm.c
++++ b/net/mptcp/pm.c
+@@ -XXX,XX +XXX,XX @@ void mptcp_pm_data_init(struct mptcp_sock *msk)
+ void __init mptcp_pm_init(void)
+ {
+     mptcp_pm_nl_init();
++    mptcp_userspace_pm_init();
+ }
+ /* Must be called with rcu read lock held */
+diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm_userspace.c
++++ b/net/mptcp/pm_userspace.c
+@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
+     return mptcp_userspace_pm_append_new_local_addr(msk, skc, true);
+ }
+-bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
+-                  struct mptcp_addr_info *skc)
++static bool mptcp_userspace_pm_get_priority(struct mptcp_sock *msk,
++                        struct mptcp_pm_param *param)
+ {
++    struct mptcp_addr_info *skc = &param->addr;
+     struct mptcp_pm_addr_entry *entry;
+     bool backup;
+@@ -XXX,XX +XXX,XX @@ bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
+     return backup;
+ }
++bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
++                  struct mptcp_addr_info *skc)
++{
++    struct mptcp_pm_param param;
++
++    mptcp_pm_param_set_contexts(&param, NULL, skc);
++    return mptcp_userspace_pm_get_priority(msk, &param);
++}
++
+ static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *info)
+ {
+     struct mptcp_sock *msk;
+@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+     sock_put(sk);
+     return ret;
+ }
++
++static struct mptcp_pm_ops mptcp_userspace_pm = {
++    .get_local_id        = mptcp_userspace_pm_get_local_id,
++    .get_priority        = mptcp_userspace_pm_get_priority,
++    .type            = MPTCP_PM_TYPE_USERSPACE,
++    .owner            = THIS_MODULE,
++};
++
++void __init mptcp_userspace_pm_init(void)
++{
++    mptcp_pm_register(&mptcp_userspace_pm);
++}
+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 @@ static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflo
+ }
+ void __init mptcp_pm_nl_init(void);
++void __init mptcp_userspace_pm_init(void);
+ void mptcp_pm_nl_work(struct mptcp_sock *msk);
+ unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
+ unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
+--
+.43.0

-New patch
+[PATCH mptcp-next v5 7/9] mptcp: pm: initialize and release mptcp_pm_ops
+From: Geliang Tang <tanggeliang@kylinos.cn>
+Add a struct mptcp_pm_ops pointer "ops" in struct mptcp_pm_data, and two
+functions mptcp_pm_initialize() and mptcp_pm_release(), to set and release
+this pointer. mptcp_pm_initialize() is invoked in mptcp_pm_data_reset(),
+while mptcp_pm_release() is invoked in __mptcp_destroy_sock().
+Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
+---
+ net/mptcp/pm.c       | 33 +++++++++++++++++++++++++++++++++
+ net/mptcp/protocol.c |  1 +
+ net/mptcp/protocol.h |  3 +++
+files changed, 37 insertions(+)
+diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm.c
++++ b/net/mptcp/pm.c
+@@ -XXX,XX +XXX,XX @@ void mptcp_pm_data_reset(struct mptcp_sock *msk)
+     pm->rm_list_tx.nr = 0;
+     pm->rm_list_rx.nr = 0;
+     WRITE_ONCE(pm->pm_type, pm_type);
++    rcu_read_lock();
++    mptcp_pm_initialize(msk, mptcp_pm_find(pm_type));
++    rcu_read_unlock();
+     if (pm_type == MPTCP_PM_TYPE_KERNEL) {
+         bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
+@@ -XXX,XX +XXX,XX @@ void mptcp_pm_unregister(struct mptcp_pm_ops *pm)
+     list_del_rcu(&pm->list);
+     spin_unlock(&mptcp_pm_list_lock);
+ }
++
++int mptcp_pm_initialize(struct mptcp_sock *msk, struct mptcp_pm_ops *pm)
++{
++    if (!pm)
++        return -EINVAL;
++
++    if (!bpf_try_module_get(pm, pm->owner))
++        return -EBUSY;
++
++    msk->pm.ops = pm;
++    if (msk->pm.ops->init)
++        msk->pm.ops->init(msk);
++
++    pr_debug("userspace_pm type %u initialized\n", msk->pm.ops->type);
++    return 0;
++}
++
++void mptcp_pm_release(struct mptcp_sock *msk)
++{
++    struct mptcp_pm_ops *pm = msk->pm.ops;
++
++    if (!pm)
++        return;
++
++    msk->pm.ops = NULL;
++    if (pm->release)
++        pm->release(msk);
++
++    bpf_module_put(pm, pm->owner);
++}
+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 void __mptcp_destroy_sock(struct sock *sk)
+     sk_stop_timer(sk, &sk->sk_timer);
+     msk->pm.status = 0;
+     mptcp_release_sched(msk);
++    mptcp_pm_release(msk);
+     sk->sk_prot->destroy(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 @@ struct mptcp_pm_data {
+     struct mptcp_addr_info remote;
+     struct list_head anno_list;
+     struct list_head userspace_pm_local_addr_list;
++    struct mptcp_pm_ops *ops;
+     spinlock_t    lock;        /*protects the whole PM data */
+@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(enum mptcp_pm_type type);
+ int mptcp_pm_validate(struct mptcp_pm_ops *pm);
+ int mptcp_pm_register(struct mptcp_pm_ops *pm);
+ void mptcp_pm_unregister(struct mptcp_pm_ops *pm);
++int mptcp_pm_initialize(struct mptcp_sock *msk, struct mptcp_pm_ops *pm);
++void mptcp_pm_release(struct mptcp_sock *msk);
+ void mptcp_free_local_addr_list(struct mptcp_sock *msk);
+--
+.43.0

-[PATCH mptcp-next v1 6/6] mptcp: pm: userspace: use sock_kmemdup helper
+[PATCH mptcp-next v5 8/9] mptcp: pm: drop get_local_id helpers
 From: Geliang Tang <tanggeliang@kylinos.cn>
-Instead of using sock_kmalloc() to allocate an entry and then
+Now mptcp_pm_nl_get_local_id() and mptcp_userspace_pm_get_local_id()
-immediately duplicate another entry to the newly allocated one,
+helpers can be dropped, and mptcp_pm_get_local_id() can directly invoke
-sock_kmemdup() helper can be used to simplify the code.
+get_local_id() interface through "ops" of "msk->pm".
 More importantly, the code "*e = *entry;" that assigns "entry"
 to "e" is not easy to implemented in BPF if we use the same code
 to implement an append_new_local_addr() helper of a BFP path
 manager. This patch avoids this type of memory assignment
 operation.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- net/mptcp/pm_userspace.c | 3 +--
+ net/mptcp/pm.c           | 6 +++---
-file changed, 1 insertion(+), 2 deletions(-)
+ net/mptcp/pm_netlink.c   | 4 ++--
  net/mptcp/pm_userspace.c | 4 ++--
  net/mptcp/protocol.h     | 4 ----
 files changed, 7 insertions(+), 11 deletions(-)
+diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm.c
++++ b/net/mptcp/pm.c
+@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
+     skc_local.addr.id = 0;
+     skc_local.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
++    if (!msk->pm.ops || !msk->pm.ops->get_local_id)
++        return -ENOTSUPP;
+     mptcp_pm_param_set_contexts(&param, &skc_local, NULL);
+-    if (mptcp_pm_is_userspace(msk))
+-        return mptcp_userspace_pm_get_local_id(msk, &param);
+-    return mptcp_pm_nl_get_local_id(msk, &param);
++    return msk->pm.ops->get_local_id(msk, &param);
+ }
+ bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
+diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm_netlink.c
++++ b/net/mptcp/pm_netlink.c
+@@ -XXX,XX +XXX,XX @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
+     return err;
+ }
+-int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
+-                 struct mptcp_pm_param *param)
++static int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
++                    struct mptcp_pm_param *param)
+ {
+     struct mptcp_pm_addr_entry *skc = &param->entry;
+     struct mptcp_pm_addr_entry *entry;
 diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_userspace.c
 +++ b/net/mptcp/pm_userspace.c
-@@ -XXX,XX +XXX,XX @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
+@@ -XXX,XX +XXX,XX @@ mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
-         /* Memory for the entry is allocated from the
+     return NULL;
-          * sock option buffer.
+ }
-          */
--        e = sock_kmalloc(sk, sizeof(*e), GFP_ATOMIC);
+-int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
-+        e = sock_kmemdup(sk, entry, sizeof(*entry), GFP_ATOMIC);
+-                    struct mptcp_pm_param *param)
-         if (!e) {
++static int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
-             ret = -ENOMEM;
++                       struct mptcp_pm_param *param)
-             goto append_err;
+ {
-         }
+     __be16 msk_sport =  ((struct inet_sock *)
+                  inet_sk((struct sock *)msk))->inet_sport;
--        *e = *entry;
+diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
-         if (!e->addr.id && needs_id)
+index XXXXXXX..XXXXXXX 100644
-             e->addr.id = find_next_zero_bit(id_bitmap,
+--- a/net/mptcp/protocol.h
-                             MPTCP_PM_MAX_ADDR_ID + 1,
++++ b/net/mptcp/protocol.h
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_param_set_contexts(struct mptcp_pm_param *param,
                   const struct mptcp_pm_addr_entry *entry,
                   const struct mptcp_addr_info *addr);
  int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 -int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
 -                 struct mptcp_pm_param *param);
 -int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 -                    struct mptcp_pm_param *param);
  bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
  bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
  bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 --
 .43.0

-[PATCH mptcp-next v1 1/6] mptcp: pm: in-kernel: avoid access entry without lock
+[PATCH mptcp-next v5 9/9] mptcp: pm: drop is_backup helpers
 From: Geliang Tang <tanggeliang@kylinos.cn>
-In mptcp_pm_nl_set_flags(), "entry" is copied to "local" when pernet->lock
+Now mptcp_pm_nl_is_backup() and mptcp_userspace_pm_is_backup()
-is held to avoid direct access to entry without pernet->lock.
+helpers can be dropped, and mptcp_pm_is_backup() can directly
+invoke get_priority() interface through "ops" of "msk->pm".
 Therefore, "local->flags" should be passed to mptcp_nl_set_flags instead
 of "entry->flags" when pernet->lock is not held, so as to avoid access to
 entry.
 Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
 ---
- net/mptcp/pm_netlink.c | 2 +-
+ net/mptcp/pm.c           | 9 +++++----
-file changed, 1 insertion(+), 1 deletion(-)
+ net/mptcp/pm_netlink.c   | 8 --------
  net/mptcp/pm_userspace.c | 9 ---------
  net/mptcp/protocol.h     | 2 --
 files changed, 5 insertions(+), 23 deletions(-)
+diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm.c
++++ b/net/mptcp/pm.c
+@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
+ bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
+ {
+     struct mptcp_addr_info skc_local;
++    struct mptcp_pm_param param;
+     mptcp_local_address((struct sock_common *)skc, &skc_local);
+-    if (mptcp_pm_is_userspace(msk))
+-        return mptcp_userspace_pm_is_backup(msk, &skc_local);
+-
+-    return mptcp_pm_nl_is_backup(msk, &skc_local);
++    if (!msk->pm.ops || !msk->pm.ops->get_priority)
++        return -ENOTSUPP;
++    mptcp_pm_param_set_contexts(&param, NULL, &skc_local);
++    return msk->pm.ops->get_priority(msk, &param);
+ }
+ static int mptcp_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
 index XXXXXXX..XXXXXXX 100644
 --- a/net/mptcp/pm_netlink.c
 +++ b/net/mptcp/pm_netlink.c
-@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
+@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_nl_get_priority(struct mptcp_sock *msk,
-     *local = *entry;
+     return backup;
      spin_unlock_bh(&pernet->lock);
 -    mptcp_nl_set_flags(net, &local->addr, entry->flags, changed);
 +    mptcp_nl_set_flags(net, &local->addr, local->flags, changed);
      return 0;
  }
+-bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
+-{
+-    struct mptcp_pm_param param;
+-
+-    mptcp_pm_param_set_contexts(&param, NULL, skc);
+-    return mptcp_pm_nl_get_priority(msk, &param);
+-}
+-
+ #define MPTCP_PM_CMD_GRP_OFFSET       0
+ #define MPTCP_PM_EV_GRP_OFFSET        1
+diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
+index XXXXXXX..XXXXXXX 100644
+--- a/net/mptcp/pm_userspace.c
++++ b/net/mptcp/pm_userspace.c
+@@ -XXX,XX +XXX,XX @@ static bool mptcp_userspace_pm_get_priority(struct mptcp_sock *msk,
+     return backup;
+ }
+-bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
+-                  struct mptcp_addr_info *skc)
+-{
+-    struct mptcp_pm_param param;
+-
+-    mptcp_pm_param_set_contexts(&param, NULL, skc);
+-    return mptcp_userspace_pm_get_priority(msk, &param);
+-}
+-
+ static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *info)
+ {
+     struct mptcp_sock *msk;
+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_pm_param_set_contexts(struct mptcp_pm_param *param,
+                  const struct mptcp_addr_info *addr);
+ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
+ bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
+-bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+-bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+ int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
+               struct netlink_callback *cb);
+ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 --
 .43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

The number of parameters in mptcp_nl_set_flags() can be reduced.
Only need to pass a "local" parameter to it instead of "local->addr"
and "local->flags".

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_netlink.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -XXX,XX +XXX,XX @@ static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
 	spin_unlock_bh(&msk->pm.lock);
 }
 
-static void mptcp_nl_set_flags(struct net *net, struct mptcp_addr_info *addr,
-			       u8 flags, u8 changed)
+static void mptcp_nl_set_flags(struct net *net,
+			       struct mptcp_pm_addr_entry *local,
+			       u8 changed)
 {
-	u8 is_subflow = !!(flags & MPTCP_PM_ADDR_FLAG_SUBFLOW);
-	u8 bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+	u8 is_subflow = !!(local->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW);
+	u8 bkup = !!(local->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
 	long s_slot = 0, s_num = 0;
 	struct mptcp_sock *msk;
 
@@ -XXX,XX +XXX,XX @@ static void mptcp_nl_set_flags(struct net *net, struct mptcp_addr_info *addr,
 
 		lock_sock(sk);
 		if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
-			mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
+			mptcp_pm_nl_mp_prio_send_ack(msk, &local->addr, NULL, bkup);
 		/* Subflows will only be recreated if the SUBFLOW flag is set */
 		if (is_subflow && (changed & MPTCP_PM_ADDR_FLAG_FULLMESH))
-			mptcp_pm_nl_fullmesh(msk, addr);
+			mptcp_pm_nl_fullmesh(msk, &local->addr);
 		release_sock(sk);
 
 next:
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
 	*local = *entry;
 	spin_unlock_bh(&pernet->lock);
 
-	mptcp_nl_set_flags(net, &local->addr, local->flags, changed);
+	mptcp_nl_set_flags(net, local, changed);
 	return 0;
 }
 
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

The following code in mptcp_userspace_pm_get_local_id() that assigns "skc"
to "new_entry" is not allowed in BPF if we use the same code to implement
the get_local_id() interface of a BFP path manager:

memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
	new_entry.addr = *skc;
	new_entry.addr.id = 0;
	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;

To solve the issue, this patch moves this assignment to "new_entry" forward
to mptcp_pm_get_local_id(), and then passing "new_entry" as a parameter to
both mptcp_pm_nl_get_local_id() and mptcp_userspace_pm_get_local_id().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           |  9 ++++++---
 net/mptcp/pm_netlink.c   | 11 ++++-------
 net/mptcp/pm_userspace.c | 17 ++++++-----------
 net/mptcp/protocol.h     |  6 ++++--
 4 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 {
-	struct mptcp_addr_info skc_local;
+	struct mptcp_pm_addr_entry skc_local = { 0 };
 	struct mptcp_addr_info msk_local;
 
 	if (WARN_ON_ONCE(!msk))
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	 * addr
 	 */
 	mptcp_local_address((struct sock_common *)msk, &msk_local);
-	mptcp_local_address((struct sock_common *)skc, &skc_local);
-	if (mptcp_addresses_equal(&msk_local, &skc_local, false))
+	mptcp_local_address((struct sock_common *)skc, &skc_local.addr);
+	if (mptcp_addresses_equal(&msk_local, &skc_local.addr, false))
 		return 0;
 
+	skc_local.addr.id = 0;
+	skc_local.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
+
 	if (mptcp_pm_is_userspace(msk))
 		return mptcp_userspace_pm_get_local_id(msk, &skc_local);
 	return mptcp_pm_nl_get_local_id(msk, &skc_local);
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -XXX,XX +XXX,XX @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 	return err;
 }
 
-int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
+int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
+			     struct mptcp_pm_addr_entry *skc)
 {
 	struct mptcp_pm_addr_entry *entry;
 	struct pm_nl_pernet *pernet;
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc
 	pernet = pm_nl_get_pernet_from_msk(msk);
 
 	rcu_read_lock();
-	entry = __lookup_addr(pernet, skc);
+	entry = __lookup_addr(pernet, &skc->addr);
 	ret = entry ? entry->addr.id : -1;
 	rcu_read_unlock();
 	if (ret >= 0)
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc
 	if (!entry)
 		return -ENOMEM;
 
-	entry->addr = *skc;
-	entry->addr.id = 0;
+	*entry = *skc;
 	entry->addr.port = 0;
-	entry->ifindex = 0;
-	entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
-	entry->lsk = NULL;
 	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
 	if (ret < 0)
 		kfree(entry);
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
 }
 
 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
-				    struct mptcp_addr_info *skc)
+				    struct mptcp_pm_addr_entry *skc)
 {
-	struct mptcp_pm_addr_entry *entry = NULL, new_entry;
 	__be16 msk_sport =  ((struct inet_sock *)
 			     inet_sk((struct sock *)msk))->inet_sport;
+	struct mptcp_pm_addr_entry *entry;
 
 	spin_lock_bh(&msk->pm.lock);
-	entry = mptcp_userspace_pm_lookup_addr(msk, skc);
+	entry = mptcp_userspace_pm_lookup_addr(msk, &skc->addr);
 	spin_unlock_bh(&msk->pm.lock);
 	if (entry)
 		return entry->addr.id;
 
-	memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
-	new_entry.addr = *skc;
-	new_entry.addr.id = 0;
-	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
-
-	if (new_entry.addr.port == msk_sport)
-		new_entry.addr.port = 0;
+	if (skc->addr.port == msk_sport)
+		skc->addr.port = 0;
 
-	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true);
+	return mptcp_userspace_pm_append_new_local_addr(msk, skc, true);
 }
 
 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
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 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			     struct mptcp_rm_list *rm_list);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
-int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
+			     struct mptcp_pm_addr_entry *skc);
+int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
+				    struct mptcp_pm_addr_entry *skc);
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Instead of using kmalloc() or kzalloc() to allocate an entry and
then immediately duplicate another entry to the newly allocated
one, kmemdup() helper can be used to simplify the code.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_netlink.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
 		return ret;
 
 	/* address not found, add to local list */
-	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+	entry = kmemdup(skc, sizeof(*skc), GFP_ATOMIC);
 	if (!entry)
 		return -ENOMEM;
 
-	*entry = *skc;
 	entry->addr.port = 0;
 	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
 	if (ret < 0)
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 
-	entry = kzalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
+	entry = kmemdup(&addr, sizeof(addr), GFP_KERNEL_ACCOUNT);
 	if (!entry) {
 		GENL_SET_ERR_MSG(info, "can't allocate addr");
 		return -ENOMEM;
 	}
 
-	*entry = addr;
 	if (entry->addr.port) {
 		ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
 		if (ret) {
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch adds the sock version of kmemdup() helper, named sock_kmemdup(),
to duplicate a memory block using the socket's option memory buffer.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/sock.h |  1 +
 net/core/sock.c    | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/net/sock.h b/include/net/sock.h
index XXXXXXX..XXXXXXX 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -XXX,XX +XXX,XX @@ static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
 }
 
 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
+void *sock_kmemdup(struct sock *sk, const void *src, int size, gfp_t priority);
 void sock_kfree_s(struct sock *sk, void *mem, int size);
 void sock_kzfree_s(struct sock *sk, void *mem, int size);
 void sk_send_sigurg(struct sock *sk);
diff --git a/net/core/sock.c b/net/core/sock.c
index XXXXXXX..XXXXXXX 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -XXX,XX +XXX,XX @@ void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
 }
 EXPORT_SYMBOL(sock_kmalloc);
 
+/*
+ * Duplicate a memory block using the socket's option memory buffer.
+ */
+void *sock_kmemdup(struct sock *sk, const void *src, int size, gfp_t priority)
+{
+	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
+
+	if ((unsigned int)size <= optmem_max &&
+	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
+		void *mem;
+		/* First do the add, to avoid the race if kmalloc
+		 * might sleep.
+		 */
+		atomic_add(size, &sk->sk_omem_alloc);
+		mem = kmemdup(src, size, priority);
+		if (mem)
+			return mem;
+		atomic_sub(size, &sk->sk_omem_alloc);
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(sock_kmemdup);
+
 /* Free an option memory block. Note, we actually want the inline
  * here as this allows gcc to detect the nullify and fold away the
  * condition entirely.
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Instead of using sock_kmalloc() to allocate an entry and then
immediately duplicate another entry to the newly allocated one,
sock_kmemdup() helper can be used to simplify the code.

More importantly, the code "*e = *entry;" that assigns "entry"
to "e" is not easy to implemented in BPF if we use the same code
to implement an append_new_local_addr() helper of a BFP path
manager. This patch avoids this type of memory assignment
operation.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_userspace.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 		/* Memory for the entry is allocated from the
 		 * sock option buffer.
 		 */
-		e = sock_kmalloc(sk, sizeof(*e), GFP_ATOMIC);
+		e = sock_kmemdup(sk, entry, sizeof(*entry), GFP_ATOMIC);
 		if (!e) {
 			ret = -ENOMEM;
 			goto append_err;
 		}
 
-		*e = *entry;
 		if (!e->addr.id && needs_id)
 			e->addr.id = find_next_zero_bit(id_bitmap,
 							MPTCP_PM_MAX_ADDR_ID + 1,
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

v5:
 - use "struct mptcp_pm_param *param" as unified parameters for all
   interfaces.
 - register in-kernel mptcp_pm_ops too.
 - only implement two interfaces "get_local_id" and "get_priority" in
   this set.

v4:
 - include a new patch "define BPF path manager type".

- add new interfaces:
	created established closed
	listerner_created listener_closed

- rename interfaces as:
	address_announced address_removed
	subflow_established subflow_closed
	get_priority set_priority

- rename functions as:
	mptcp_pm_validate
	mptcp_pm_register
	mptcp_pm_unregister
	mptcp_pm_initialize
	mptcp_pm_release

v3:
 - rename the 2nd parameter of get_local_id() from 'local' to 'skc'.
 - keep the 'msk_sport' check in mptcp_userspace_pm_get_local_id().
 - return 'err' instead of '0' in userspace_pm_subflow_create().
 - drop 'ret' variable inmptcp_pm_data_reset().
 - fix typos in commit log.

v2:
 - update get_local_id interface in patch 2.

get_addr() and dump_addr() interfaces of BPF userspace pm are dropped
as Matt suggested.

In order to implement BPF path manager, it's necessary to unify the
interfaces of the path manager. This set contains some cleanups and
refactoring to unify the interfaces in kernel space. Finally, define
a struct mptcp_pm_ops for a path manager.

Geliang Tang (9):
  mptcp: pm: use addr entry for get_local_id
  mptcp: pm: add struct mptcp_pm_param
  mptcp: pm: pass pm_param to get_local_id
  mptcp: pm: define struct mptcp_pm_ops
  mptcp: pm: in-kernel: register mptcp_netlink_pm
  mptcp: pm: userspace: register mptcp_userspace_pm
  mptcp: pm: initialize and release mptcp_pm_ops
  mptcp: pm: drop get_local_id helpers
  mptcp: pm: drop is_backup helpers

-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
	new_entry.addr = *skc;
	new_entry.addr.id = 0;
	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 11 ++++++++---
 net/mptcp/pm_netlink.c   |  9 ++++-----
 net/mptcp/pm_userspace.c | 17 ++++++-----------
 net/mptcp/protocol.h     |  6 ++++--
 4 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 {
-	struct mptcp_addr_info skc_local;
+	struct mptcp_pm_addr_entry skc_local;
 	struct mptcp_addr_info msk_local;
 
 	if (WARN_ON_ONCE(!msk))
 		return -1;
 
+	memset(&skc_local, 0, sizeof(struct mptcp_pm_addr_entry));
+
 	/* The 0 ID mapping is defined by the first subflow, copied into the msk
 	 * addr
 	 */
 	mptcp_local_address((struct sock_common *)msk, &msk_local);
-	mptcp_local_address((struct sock_common *)skc, &skc_local);
-	if (mptcp_addresses_equal(&msk_local, &skc_local, false))
+	mptcp_local_address((struct sock_common *)skc, &skc_local.addr);
+	if (mptcp_addresses_equal(&msk_local, &skc_local.addr, false))
 		return 0;
 
+	skc_local.addr.id = 0;
+	skc_local.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
+
 	if (mptcp_pm_is_userspace(msk))
 		return mptcp_userspace_pm_get_local_id(msk, &skc_local);
 	return mptcp_pm_nl_get_local_id(msk, &skc_local);
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -XXX,XX +XXX,XX @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 	return err;
 }
 
-int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
+int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
+			     struct mptcp_pm_addr_entry *skc)
 {
 	struct mptcp_pm_addr_entry *entry;
 	struct pm_nl_pernet *pernet;
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc
 	pernet = pm_nl_get_pernet_from_msk(msk);
 
 	rcu_read_lock();
-	entry = __lookup_addr(pernet, skc);
+	entry = __lookup_addr(pernet, &skc->addr);
 	ret = entry ? entry->addr.id : -1;
 	rcu_read_unlock();
 	if (ret >= 0)
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc
 	if (!entry)
 		return -ENOMEM;
 
-	entry->addr = *skc;
-	entry->addr.id = 0;
+	*entry = *skc;
 	entry->addr.port = 0;
 	entry->ifindex = 0;
-	entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
 	entry->lsk = NULL;
 	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
 	if (ret < 0)
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
 }
 
 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
-				    struct mptcp_addr_info *skc)
+				    struct mptcp_pm_addr_entry *skc)
 {
-	struct mptcp_pm_addr_entry *entry = NULL, new_entry;
 	__be16 msk_sport =  ((struct inet_sock *)
 			     inet_sk((struct sock *)msk))->inet_sport;
+	struct mptcp_pm_addr_entry *entry;
 
 	spin_lock_bh(&msk->pm.lock);
-	entry = mptcp_userspace_pm_lookup_addr(msk, skc);
+	entry = mptcp_userspace_pm_lookup_addr(msk, &skc->addr);
 	spin_unlock_bh(&msk->pm.lock);
 	if (entry)
 		return entry->addr.id;
 
-	memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
-	new_entry.addr = *skc;
-	new_entry.addr.id = 0;
-	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
-
-	if (new_entry.addr.port == msk_sport)
-		new_entry.addr.port = 0;
+	if (skc->addr.port == msk_sport)
+		skc->addr.port = 0;
 
-	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true);
+	return mptcp_userspace_pm_append_new_local_addr(msk, skc, true);
 }
 
 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
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 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			     struct mptcp_rm_list *rm_list);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
-int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
+int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
+			     struct mptcp_pm_addr_entry *skc);
+int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
+				    struct mptcp_pm_addr_entry *skc);
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Generally, in the path manager interfaces, the local address is defined
as an mptcp_pm_addr_entry type address, while the remote address is
defined as an mptcp_addr_info type one:

(struct mptcp_pm_addr_entry *local, struct mptcp_addr_info *remote)

In order to make these interfaces more flexible and extensible, a struct
mptcp_pm_param is defined here to pass parameters. "entry" can be used
as the local address entry, and "addr" can be used as the remote address.

Also add a new helper mptcp_pm_param_set_contexts() to set a struct
mptcp_pm_param type parameter.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h  | 13 +++++++++++++
 net/mptcp/pm.c       | 10 ++++++++++
 net/mptcp/protocol.h | 11 +++--------
 3 files changed, 26 insertions(+), 8 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_sched_ops {
 	void (*release)(struct mptcp_sock *msk);
 } ____cacheline_aligned_in_smp;
 
+struct mptcp_pm_addr_entry {
+	struct list_head	list;
+	struct mptcp_addr_info	addr;
+	u8			flags;
+	int			ifindex;
+	struct socket		*lsk;
+};
+
+struct mptcp_pm_param {
+	struct mptcp_pm_addr_entry	entry;
+	struct mptcp_addr_info		addr;
+};
+
 #ifdef CONFIG_MPTCP
 void mptcp_init(void);
 
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 	return ret;
 }
 
+void mptcp_pm_param_set_contexts(struct mptcp_pm_param *param,
+				 const struct mptcp_pm_addr_entry *entry,
+				 const struct mptcp_addr_info *addr)
+{
+	if (entry)
+		param->entry = *entry;
+	if (addr)
+		param->addr = *addr;
+}
+
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 {
 	struct mptcp_pm_addr_entry skc_local;
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 @@ struct mptcp_pm_local {
 	int			ifindex;
 };
 
-struct mptcp_pm_addr_entry {
-	struct list_head	list;
-	struct mptcp_addr_info	addr;
-	u8			flags;
-	int			ifindex;
-	struct socket		*lsk;
-};
-
 struct mptcp_data_frag {
 	struct list_head list;
 	u64 data_seq;
@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 			      bool *drop_other_suboptions);
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			     struct mptcp_rm_list *rm_list);
+void mptcp_pm_param_set_contexts(struct mptcp_pm_param *param,
+				 const struct mptcp_pm_addr_entry *entry,
+				 const struct mptcp_addr_info *addr);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
 			     struct mptcp_pm_addr_entry *skc);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch changes the 2nd parameter of get_local_id() interface as
"struct mptcp_pm_param" type. Only "entry" member of this struct is
used.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 6 ++++--
 net/mptcp/pm_netlink.c   | 3 ++-
 net/mptcp/pm_userspace.c | 3 ++-
 net/mptcp/protocol.h     | 4 ++--
 4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 {
 	struct mptcp_pm_addr_entry skc_local;
 	struct mptcp_addr_info msk_local;
+	struct mptcp_pm_param param;
 
 	if (WARN_ON_ONCE(!msk))
 		return -1;
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	skc_local.addr.id = 0;
 	skc_local.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
 
+	mptcp_pm_param_set_contexts(&param, &skc_local, NULL);
 	if (mptcp_pm_is_userspace(msk))
-		return mptcp_userspace_pm_get_local_id(msk, &skc_local);
-	return mptcp_pm_nl_get_local_id(msk, &skc_local);
+		return mptcp_userspace_pm_get_local_id(msk, &param);
+	return mptcp_pm_nl_get_local_id(msk, &param);
 }
 
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -XXX,XX +XXX,XX @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 }
 
 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
-			     struct mptcp_pm_addr_entry *skc)
+			     struct mptcp_pm_param *param)
 {
+	struct mptcp_pm_addr_entry *skc = &param->entry;
 	struct mptcp_pm_addr_entry *entry;
 	struct pm_nl_pernet *pernet;
 	int ret;
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
 }
 
 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
-				    struct mptcp_pm_addr_entry *skc)
+				    struct mptcp_pm_param *param)
 {
 	__be16 msk_sport =  ((struct inet_sock *)
 			     inet_sk((struct sock *)msk))->inet_sport;
+	struct mptcp_pm_addr_entry *skc = &param->entry;
 	struct mptcp_pm_addr_entry *entry;
 
 	spin_lock_bh(&msk->pm.lock);
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_pm_param_set_contexts(struct mptcp_pm_param *param,
 				 const struct mptcp_addr_info *addr);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
-			     struct mptcp_pm_addr_entry *skc);
+			     struct mptcp_pm_param *param);
 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
-				    struct mptcp_pm_addr_entry *skc);
+				    struct mptcp_pm_param *param);
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

In order to allow users to develop their own BPF-based path manager,
this patch defines a struct ops "mptcp_pm_ops" for a userspace path
manager, which contains a set of interfaces.

Add a set of functions to register, unregister, find and validate a
given struct ops.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h  | 29 ++++++++++++++++++++++
 net/mptcp/pm.c       | 59 ++++++++++++++++++++++++++++++++++++++++++++
 net/mptcp/protocol.h |  5 ++++
 3 files changed, 93 insertions(+)

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_pm_param {
 	struct mptcp_addr_info		addr;
 };
 
+struct mptcp_pm_ops {
+	int (*created)(struct mptcp_sock *msk);
+	int (*established)(struct mptcp_sock *msk);
+	int (*closed)(struct mptcp_sock *msk);
+	int (*address_announced)(struct mptcp_sock *msk,
+				 struct mptcp_pm_param *param);
+	int (*address_removed)(struct mptcp_sock *msk,
+			       struct mptcp_pm_param *param);
+	int (*subflow_established)(struct mptcp_sock *msk,
+				   struct mptcp_pm_param *param);
+	int (*subflow_closed)(struct mptcp_sock *msk,
+			      struct mptcp_pm_param *param);
+	int (*get_local_id)(struct mptcp_sock *msk,
+			    struct mptcp_pm_param *param);
+	bool (*get_priority)(struct mptcp_sock *msk,
+			     struct mptcp_pm_param *param);
+	int (*set_priority)(struct mptcp_sock *msk,
+			    struct mptcp_pm_param *param);
+	int (*listener_created)(struct mptcp_sock *msk);
+	int (*listener_closed)(struct mptcp_sock *msk);
+
+	u8			type;
+	struct module		*owner;
+	struct list_head	list;
+
+	void (*init)(struct mptcp_sock *msk);
+	void (*release)(struct mptcp_sock *msk);
+} ____cacheline_aligned_in_smp;
+
 #ifdef CONFIG_MPTCP
 void mptcp_init(void);
 
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@
 #define pr_fmt(fmt) "MPTCP: " fmt
 
 #include <linux/kernel.h>
+#include <linux/rculist.h>
+#include <linux/spinlock.h>
 #include <net/mptcp.h>
 #include "protocol.h"
 
 #include "mib.h"
 #include "mptcp_pm_gen.h"
 
+static DEFINE_SPINLOCK(mptcp_pm_list_lock);
+static LIST_HEAD(mptcp_pm_list);
+
 /* path manager command handlers */
 
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
@@ -XXX,XX +XXX,XX @@ void __init mptcp_pm_init(void)
 {
 	mptcp_pm_nl_init();
 }
+
+/* Must be called with rcu read lock held */
+struct mptcp_pm_ops *mptcp_pm_find(enum mptcp_pm_type type)
+{
+	struct mptcp_pm_ops *pm;
+
+	list_for_each_entry_rcu(pm, &mptcp_pm_list, list) {
+		if (pm->type == type)
+			return pm;
+	}
+
+	return NULL;
+}
+
+int mptcp_pm_validate(struct mptcp_pm_ops *pm)
+{
+	if (!pm->created && !pm->established && !pm->closed &&
+	    !pm->address_announced && !pm->address_removed &&
+	    !pm->subflow_established && !pm->subflow_closed &&
+	    !pm->get_local_id && !pm->get_priority && !pm->set_priority &&
+	    !pm->listener_created && !pm->listener_closed) {
+		pr_err("%u does not implement required ops\n", pm->type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int mptcp_pm_register(struct mptcp_pm_ops *pm)
+{
+	int ret;
+
+	ret = mptcp_pm_validate(pm);
+	if (ret)
+		return ret;
+
+	spin_lock(&mptcp_pm_list_lock);
+	if (mptcp_pm_find(pm->type)) {
+		spin_unlock(&mptcp_pm_list_lock);
+		return -EEXIST;
+	}
+	list_add_tail_rcu(&pm->list, &mptcp_pm_list);
+	spin_unlock(&mptcp_pm_list_lock);
+
+	pr_debug("userspace_pm type %u registered\n", pm->type);
+	return 0;
+}
+
+void mptcp_pm_unregister(struct mptcp_pm_ops *pm)
+{
+	spin_lock(&mptcp_pm_list_lock);
+	list_del_rcu(&pm->list);
+	spin_unlock(&mptcp_pm_list_lock);
+}
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 @@ int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_
 void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
 				struct mptcp_pm_addr_entry *entry);
 
+struct mptcp_pm_ops *mptcp_pm_find(enum mptcp_pm_type type);
+int mptcp_pm_validate(struct mptcp_pm_ops *pm);
+int mptcp_pm_register(struct mptcp_pm_ops *pm);
+void mptcp_pm_unregister(struct mptcp_pm_ops *pm);
+
 void mptcp_free_local_addr_list(struct mptcp_sock *msk);
 
 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch defines the original in-kernel netlink path manager as a new
struct mptcp_pm_ops named "mptcp_netlink_pm", and register it in
mptcp_pm_nl_init().

Only get_local_id() and get_priority() interfaces are implemented here.
mptcp_pm_nl_is_backup() becomes a wrapper of get_priority().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_netlink.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
 	return ret;
 }
 
-bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
+static bool mptcp_pm_nl_get_priority(struct mptcp_sock *msk,
+				     struct mptcp_pm_param *param)
 {
 	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
+	struct mptcp_addr_info *skc = &param->addr;
 	struct mptcp_pm_addr_entry *entry;
 	bool backup;
 
@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
 	return backup;
 }
 
+bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
+{
+	struct mptcp_pm_param param;
+
+	mptcp_pm_param_set_contexts(&param, NULL, skc);
+	return mptcp_pm_nl_get_priority(msk, &param);
+}
+
 #define MPTCP_PM_CMD_GRP_OFFSET       0
 #define MPTCP_PM_EV_GRP_OFFSET        1
 
@@ -XXX,XX +XXX,XX @@ static struct pernet_operations mptcp_pm_pernet_ops = {
 	.size = sizeof(struct pm_nl_pernet),
 };
 
+static struct mptcp_pm_ops mptcp_netlink_pm = {
+	.get_local_id		= mptcp_pm_nl_get_local_id,
+	.get_priority		= mptcp_pm_nl_get_priority,
+	.type			= MPTCP_PM_TYPE_KERNEL,
+	.owner			= THIS_MODULE,
+};
+
 void __init mptcp_pm_nl_init(void)
 {
 	if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
@@ -XXX,XX +XXX,XX @@ void __init mptcp_pm_nl_init(void)
 
 	if (genl_register_family(&mptcp_genl_family))
 		panic("Failed to register MPTCP PM netlink family\n");
+
+	mptcp_pm_register(&mptcp_netlink_pm);
 }
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch defines the original userspace path manager as a new struct
mptcp_pm_ops named "mptcp_userspace_pm", and register it in
mptcp_pm_data_init().

Only get_local_id() and get_priority() interfaces are implemented here.
mptcp_userspace_pm_is_backup() becomes a wrapper of get_priority().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           |  1 +
 net/mptcp/pm_userspace.c | 26 ++++++++++++++++++++++++--
 net/mptcp/protocol.h     |  1 +
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_data_init(struct mptcp_sock *msk)
 void __init mptcp_pm_init(void)
 {
 	mptcp_pm_nl_init();
+	mptcp_userspace_pm_init();
 }
 
 /* Must be called with rcu read lock held */
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 	return mptcp_userspace_pm_append_new_local_addr(msk, skc, true);
 }
 
-bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
-				  struct mptcp_addr_info *skc)
+static bool mptcp_userspace_pm_get_priority(struct mptcp_sock *msk,
+					    struct mptcp_pm_param *param)
 {
+	struct mptcp_addr_info *skc = &param->addr;
 	struct mptcp_pm_addr_entry *entry;
 	bool backup;
 
@@ -XXX,XX +XXX,XX @@ bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
 	return backup;
 }
 
+bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
+				  struct mptcp_addr_info *skc)
+{
+	struct mptcp_pm_param param;
+
+	mptcp_pm_param_set_contexts(&param, NULL, skc);
+	return mptcp_userspace_pm_get_priority(msk, &param);
+}
+
 static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *info)
 {
 	struct mptcp_sock *msk;
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 	sock_put(sk);
 	return ret;
 }
+
+static struct mptcp_pm_ops mptcp_userspace_pm = {
+	.get_local_id		= mptcp_userspace_pm_get_local_id,
+	.get_priority		= mptcp_userspace_pm_get_priority,
+	.type			= MPTCP_PM_TYPE_USERSPACE,
+	.owner			= THIS_MODULE,
+};
+
+void __init mptcp_userspace_pm_init(void)
+{
+	mptcp_pm_register(&mptcp_userspace_pm);
+}
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 @@ static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflo
 }
 
 void __init mptcp_pm_nl_init(void);
+void __init mptcp_userspace_pm_init(void);
 void mptcp_pm_nl_work(struct mptcp_sock *msk);
 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk);
 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Add a struct mptcp_pm_ops pointer "ops" in struct mptcp_pm_data, and two
functions mptcp_pm_initialize() and mptcp_pm_release(), to set and release
this pointer. mptcp_pm_initialize() is invoked in mptcp_pm_data_reset(),
while mptcp_pm_release() is invoked in __mptcp_destroy_sock().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c       | 33 +++++++++++++++++++++++++++++++++
 net/mptcp/protocol.c |  1 +
 net/mptcp/protocol.h |  3 +++
 3 files changed, 37 insertions(+)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_data_reset(struct mptcp_sock *msk)
 	pm->rm_list_tx.nr = 0;
 	pm->rm_list_rx.nr = 0;
 	WRITE_ONCE(pm->pm_type, pm_type);
+	rcu_read_lock();
+	mptcp_pm_initialize(msk, mptcp_pm_find(pm_type));
+	rcu_read_unlock();
 
 	if (pm_type == MPTCP_PM_TYPE_KERNEL) {
 		bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
@@ -XXX,XX +XXX,XX @@ void mptcp_pm_unregister(struct mptcp_pm_ops *pm)
 	list_del_rcu(&pm->list);
 	spin_unlock(&mptcp_pm_list_lock);
 }
+
+int mptcp_pm_initialize(struct mptcp_sock *msk, struct mptcp_pm_ops *pm)
+{
+	if (!pm)
+		return -EINVAL;
+
+	if (!bpf_try_module_get(pm, pm->owner))
+		return -EBUSY;
+
+	msk->pm.ops = pm;
+	if (msk->pm.ops->init)
+		msk->pm.ops->init(msk);
+
+	pr_debug("userspace_pm type %u initialized\n", msk->pm.ops->type);
+	return 0;
+}
+
+void mptcp_pm_release(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_ops *pm = msk->pm.ops;
+
+	if (!pm)
+		return;
+
+	msk->pm.ops = NULL;
+	if (pm->release)
+		pm->release(msk);
+
+	bpf_module_put(pm, pm->owner);
+}
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 void __mptcp_destroy_sock(struct sock *sk)
 	sk_stop_timer(sk, &sk->sk_timer);
 	msk->pm.status = 0;
 	mptcp_release_sched(msk);
+	mptcp_pm_release(msk);
 
 	sk->sk_prot->destroy(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 @@ struct mptcp_pm_data {
 	struct mptcp_addr_info remote;
 	struct list_head anno_list;
 	struct list_head userspace_pm_local_addr_list;
+	struct mptcp_pm_ops *ops;
 
 	spinlock_t	lock;		/*protects the whole PM data */
 
@@ -XXX,XX +XXX,XX @@ struct mptcp_pm_ops *mptcp_pm_find(enum mptcp_pm_type type);
 int mptcp_pm_validate(struct mptcp_pm_ops *pm);
 int mptcp_pm_register(struct mptcp_pm_ops *pm);
 void mptcp_pm_unregister(struct mptcp_pm_ops *pm);
+int mptcp_pm_initialize(struct mptcp_sock *msk, struct mptcp_pm_ops *pm);
+void mptcp_pm_release(struct mptcp_sock *msk);
 
 void mptcp_free_local_addr_list(struct mptcp_sock *msk);
 
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Now mptcp_pm_nl_get_local_id() and mptcp_userspace_pm_get_local_id()
helpers can be dropped, and mptcp_pm_get_local_id() can directly invoke
get_local_id() interface through "ops" of "msk->pm".

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 6 +++---
 net/mptcp/pm_netlink.c   | 4 ++--
 net/mptcp/pm_userspace.c | 4 ++--
 net/mptcp/protocol.h     | 4 ----
 4 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	skc_local.addr.id = 0;
 	skc_local.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
 
+	if (!msk->pm.ops || !msk->pm.ops->get_local_id)
+		return -ENOTSUPP;
 	mptcp_pm_param_set_contexts(&param, &skc_local, NULL);
-	if (mptcp_pm_is_userspace(msk))
-		return mptcp_userspace_pm_get_local_id(msk, &param);
-	return mptcp_pm_nl_get_local_id(msk, &param);
+	return msk->pm.ops->get_local_id(msk, &param);
 }
 
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -XXX,XX +XXX,XX @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 	return err;
 }
 
-int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
-			     struct mptcp_pm_param *param)
+static int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
+				    struct mptcp_pm_param *param)
 {
 	struct mptcp_pm_addr_entry *skc = &param->entry;
 	struct mptcp_pm_addr_entry *entry;
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
 	return NULL;
 }
 
-int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
-				    struct mptcp_pm_param *param)
+static int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
+					   struct mptcp_pm_param *param)
 {
 	__be16 msk_sport =  ((struct inet_sock *)
 			     inet_sk((struct sock *)msk))->inet_sport;
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_pm_param_set_contexts(struct mptcp_pm_param *param,
 				 const struct mptcp_pm_addr_entry *entry,
 				 const struct mptcp_addr_info *addr);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
-int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
-			     struct mptcp_pm_param *param);
-int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
-				    struct mptcp_pm_param *param);
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-- 
2.43.0

From: Geliang Tang <tanggeliang@kylinos.cn>

Now mptcp_pm_nl_is_backup() and mptcp_userspace_pm_is_backup()
helpers can be dropped, and mptcp_pm_is_backup() can directly
invoke get_priority() interface through "ops" of "msk->pm".

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 9 +++++----
 net/mptcp/pm_netlink.c   | 8 --------
 net/mptcp/pm_userspace.c | 9 ---------
 net/mptcp/protocol.h     | 2 --
 4 files changed, 5 insertions(+), 23 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
 {
 	struct mptcp_addr_info skc_local;
+	struct mptcp_pm_param param;
 
 	mptcp_local_address((struct sock_common *)skc, &skc_local);
 
-	if (mptcp_pm_is_userspace(msk))
-		return mptcp_userspace_pm_is_backup(msk, &skc_local);
-
-	return mptcp_pm_nl_is_backup(msk, &skc_local);
+	if (!msk->pm.ops || !msk->pm.ops->get_priority)
+		return -ENOTSUPP;
+	mptcp_pm_param_set_contexts(&param, NULL, &skc_local);
+	return msk->pm.ops->get_priority(msk, &param);
 }
 
 static int mptcp_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_pm_nl_get_priority(struct mptcp_sock *msk,
 	return backup;
 }
 
-bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
-{
-	struct mptcp_pm_param param;
-
-	mptcp_pm_param_set_contexts(&param, NULL, skc);
-	return mptcp_pm_nl_get_priority(msk, &param);
-}
-
 #define MPTCP_PM_CMD_GRP_OFFSET       0
 #define MPTCP_PM_EV_GRP_OFFSET        1
 
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index XXXXXXX..XXXXXXX 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -XXX,XX +XXX,XX @@ static bool mptcp_userspace_pm_get_priority(struct mptcp_sock *msk,
 	return backup;
 }
 
-bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
-				  struct mptcp_addr_info *skc)
-{
-	struct mptcp_pm_param param;
-
-	mptcp_pm_param_set_contexts(&param, NULL, skc);
-	return mptcp_userspace_pm_get_priority(msk, &param);
-}
-
 static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *info)
 {
 	struct mptcp_sock *msk;
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_pm_param_set_contexts(struct mptcp_pm_param *param,
 				 const struct mptcp_addr_info *addr);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
-bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb);
 int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
-- 
2.43.0