Series comparison

From: Geliang Tang <tanggeliang@kylinos.cn>

Three netlink functions:

mptcp_pm_nl_get_addr_doit()
	mptcp_pm_nl_get_addr_dumpit()
	mptcp_pm_nl_set_flags_doit()

are generic, implemented for each PM, in-kernel PM and userspace PM. It's
clearer to move them from pm_netlink.c to pm.c.

And the linked three path manager wrappers

mptcp_pm_get_addr()
	mptcp_pm_dump_addr()
	mptcp_pm_set_flags()

can be changed as static functions, no need to export them in protocol.h.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c         | 23 ++++++++++++++++++++---
 net/mptcp/pm_netlink.c | 16 ----------------
 net/mptcp/protocol.h   |  3 ---
 3 files changed, 20 insertions(+), 22 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 @@
 #include "protocol.h"
 
 #include "mib.h"
+#include "mptcp_pm_gen.h"
 
 /* path manager command handlers */
 
@@ -XXX,XX +XXX,XX @@ bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
 	return mptcp_pm_nl_is_backup(msk, &skc_local);
 }
 
-int mptcp_pm_get_addr(struct sk_buff *skb, struct genl_info *info)
+static int mptcp_pm_get_addr(struct sk_buff *skb, struct genl_info *info)
 {
 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
 		return mptcp_userspace_pm_get_addr(skb, info);
 	return mptcp_pm_nl_get_addr(skb, info);
 }
 
-int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
+int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	return mptcp_pm_get_addr(skb, info);
+}
+
+static int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
 {
 	const struct genl_info *info = genl_info_dump(cb);
 
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
 	return mptcp_pm_nl_dump_addr(msg, cb);
 }
 
-int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
+int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
+				struct netlink_callback *cb)
+{
+	return mptcp_pm_dump_addr(msg, cb);
+}
+
+static int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
 {
 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
 		return mptcp_userspace_pm_set_flags(skb, info);
 	return mptcp_pm_nl_set_flags(skb, info);
 }
 
+int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	return mptcp_pm_set_flags(skb, info);
+}
+
 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
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_addr(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
-{
-	return mptcp_pm_get_addr(skb, info);
-}
-
 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb)
 {
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 	return msg->len;
 }
 
-int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
-				struct netlink_callback *cb)
-{
-	return mptcp_pm_dump_addr(msg, cb);
-}
-
 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
 {
 	struct nlattr *attr = info->attrs[id];
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
 	return 0;
 }
 
-int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
-{
-	return mptcp_pm_set_flags(skb, info);
-}
-
 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
 {
 	genlmsg_multicast_netns(&mptcp_genl_family, net,
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_lookup_subflow_by_saddr(const struct list_head *list,
 				   const struct mptcp_addr_info *saddr);
 bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
 				     const struct mptcp_addr_info *addr);
-int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info);
 int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info);
 int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info);
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_in
 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_dump_addr(struct sk_buff *msg, struct netlink_callback *cb);
 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb);
 int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 				 struct netlink_callback *cb);
-int mptcp_pm_get_addr(struct sk_buff *skb, struct genl_info *info);
 int mptcp_pm_nl_get_addr(struct sk_buff *skb, struct genl_info *info);
 int mptcp_userspace_pm_get_addr(struct sk_buff *skb,
 				struct genl_info *info);
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

The first parameters "skb" of all three get_addr() interfaces are now
useless since mptcp_userspace_pm_get_sock() helper is used. This patch
drops these useless parameters of them.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 8 ++++----
 net/mptcp/pm_netlink.c   | 2 +-
 net/mptcp/pm_userspace.c | 3 +--
 net/mptcp/protocol.h     | 5 ++---
 4 files changed, 8 insertions(+), 10 deletions(-)

From: Geliang Tang <tanggeliang@kylinos.cn>

The address id is parsed both in mptcp_pm_nl_get_addr() and
mptcp_userspace_pm_get_addr(), this makes the code somewhat repetitive.
So this patch adds a new parameter "id" for all get_addr() interfaces.
The address id is only parsed in mptcp_pm_nl_get_addr_doit(), then pass
it to both mptcp_pm_nl_get_addr() and mptcp_userspace_pm_get_addr().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 16 ++++++++++++----
 net/mptcp/pm_netlink.c   | 11 +++--------
 net/mptcp/pm_userspace.c | 11 +++--------
 net/mptcp/protocol.h     |  4 ++--
 4 files changed, 20 insertions(+), 22 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_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
 	return mptcp_pm_nl_is_backup(msk, &skc_local);
 }
 
-static int mptcp_pm_get_addr(struct genl_info *info)
+static int mptcp_pm_get_addr(u8 id, struct genl_info *info)
 {
 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
-		return mptcp_userspace_pm_get_addr(info);
-	return mptcp_pm_nl_get_addr(info);
+		return mptcp_userspace_pm_get_addr(id, info);
+	return mptcp_pm_nl_get_addr(id, info);
 }
 
 int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	return mptcp_pm_get_addr(info);
+	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
+	struct mptcp_pm_addr_entry addr;
+	int ret;
+
+	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
+	if (ret < 0)
+		return ret;
+
+	return mptcp_pm_get_addr(addr.addr.id, info);
 }
 
 static int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
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_nl_fill_addr(struct sk_buff *skb,
 	return -EMSGSIZE;
 }
 
-int mptcp_pm_nl_get_addr(struct genl_info *info)
+int mptcp_pm_nl_get_addr(u8 id, struct genl_info *info)
 {
-	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
-	struct mptcp_pm_addr_entry addr, *entry;
+	struct mptcp_pm_addr_entry *entry;
 	struct sk_buff *msg;
 	void *reply;
 	int ret;
 
-	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
-	if (ret < 0)
-		return ret;
-
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;
@@ -XXX,XX +XXX,XX @@ int mptcp_pm_nl_get_addr(struct genl_info *info)
 	}
 
 	rcu_read_lock();
-	entry = __lookup_addr_by_id(pernet, addr.addr.id);
+	entry = __lookup_addr_by_id(pernet, id);
 	if (!entry) {
 		GENL_SET_ERR_MSG(info, "address not found");
 		ret = -EINVAL;
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_dump_addr(struct sk_buff *msg,
 	return ret;
 }
 
-int mptcp_userspace_pm_get_addr(struct genl_info *info)
+int mptcp_userspace_pm_get_addr(u8 id, struct genl_info *info)
 {
-	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
-	struct mptcp_pm_addr_entry addr, *entry;
+	struct mptcp_pm_addr_entry *entry;
 	struct mptcp_sock *msk;
 	struct sk_buff *msg;
 	int ret = -EINVAL;
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(struct genl_info *info)
 
 	sk = (struct sock *)msk;
 
-	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
-	if (ret < 0)
-		goto out;
-
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg) {
 		ret = -ENOMEM;
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(struct genl_info *info)
 
 	lock_sock(sk);
 	spin_lock_bh(&msk->pm.lock);
-	entry = mptcp_userspace_pm_lookup_addr_by_id(msk, addr.addr.id);
+	entry = mptcp_userspace_pm_lookup_addr_by_id(msk, id);
 	if (!entry) {
 		GENL_SET_ERR_MSG(info, "address not found");
 		ret = -EINVAL;
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_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb);
 int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 				 struct netlink_callback *cb);
-int mptcp_pm_nl_get_addr(struct genl_info *info);
-int mptcp_userspace_pm_get_addr(struct genl_info *info);
+int mptcp_pm_nl_get_addr(u8 id, struct genl_info *info);
+int mptcp_userspace_pm_get_addr(u8 id, struct genl_info *info);
 
 static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflow)
 {
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

The netlink messages are sent both in mptcp_pm_nl_get_addr() and
mptcp_userspace_pm_get_addr(), this makes the code somewhat repetitive.
This is because the netlink PM and userspace PM use different locks to
protect the address entry that needs to be sent via the netlink message.
The former uses rcu read lock, and the latter uses msk->pm.lock.

The current get_addr() flow looks like this:

lock();
	entry = get_entry();
	send_nlmsg(entry);
	unlock();

After holding the lock, get the entry from the list, send the entry, and
finally release the lock.

This patch changes the process by getting the entry while holding the lock,
then making a copy of the entry so that the lock can be released. Finally,
the copy of the entry is sent without locking:

lock();
	entry = get_entry();
	*copy = *entry;
	unlock();

send_nlmsg(copy);

This way we can reuse the send_nlmsg() code in get_addr() interfaces
between the netlink PM and userspace PM. They only need to implement their
own get_addr() interfaces to hold the different locks, get the entry from
the different lists, then release the locks.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 39 ++++++++++++++++++++++++++++++++++----
 net/mptcp/pm_netlink.c   | 39 ++++++--------------------------------
 net/mptcp/pm_userspace.c | 41 +++++-----------------------------------
 net/mptcp/protocol.h     |  6 ++++--
 4 files changed, 50 insertions(+), 75 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_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
 	return mptcp_pm_nl_is_backup(msk, &skc_local);
 }
 
-static int mptcp_pm_get_addr(u8 id, struct genl_info *info)
+static int mptcp_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+			     struct genl_info *info)
 {
 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
-		return mptcp_userspace_pm_get_addr(id, info);
-	return mptcp_pm_nl_get_addr(id, info);
+		return mptcp_userspace_pm_get_addr(id, addr, info);
+	return mptcp_pm_nl_get_addr(id, addr, info);
 }
 
 int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
 	struct mptcp_pm_addr_entry addr;
+	struct sk_buff *msg;
+	void *reply;
 	int ret;
 
 	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
 	if (ret < 0)
 		return ret;
 
-	return mptcp_pm_get_addr(addr.addr.id, info);
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
+				  info->genlhdr->cmd);
+	if (!reply) {
+		GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
+		ret = -EMSGSIZE;
+		goto fail;
+	}
+
+	ret = mptcp_pm_get_addr(addr.addr.id, &addr, info);
+	if (ret) {
+		GENL_SET_ERR_MSG(info, "address not found");
+		goto fail;
+	}
+
+	ret = mptcp_nl_fill_addr(msg, &addr);
+	if (ret)
+		goto fail;
+
+	genlmsg_end(msg, reply);
+	ret = genlmsg_reply(msg, info);
+	return ret;
+
+fail:
+	nlmsg_free(msg);
+	return ret;
 }
 
 static int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
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_nl_fill_addr(struct sk_buff *skb,
 	return -EMSGSIZE;
 }
 
-int mptcp_pm_nl_get_addr(u8 id, struct genl_info *info)
+int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+			 struct genl_info *info)
 {
 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
 	struct mptcp_pm_addr_entry *entry;
-	struct sk_buff *msg;
-	void *reply;
-	int ret;
-
-	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-	if (!msg)
-		return -ENOMEM;
-
-	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
-				  info->genlhdr->cmd);
-	if (!reply) {
-		GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
-		ret = -EMSGSIZE;
-		goto fail;
-	}
+	int ret = -EINVAL;
 
 	rcu_read_lock();
 	entry = __lookup_addr_by_id(pernet, id);
-	if (!entry) {
-		GENL_SET_ERR_MSG(info, "address not found");
-		ret = -EINVAL;
-		goto unlock_fail;
+	if (entry) {
+		*addr = *entry;
+		ret = 0;
 	}
-
-	ret = mptcp_nl_fill_addr(msg, entry);
-	if (ret)
-		goto unlock_fail;
-
-	genlmsg_end(msg, reply);
-	ret = genlmsg_reply(msg, info);
-	rcu_read_unlock();
-	return ret;
-
-unlock_fail:
 	rcu_read_unlock();
 
-fail:
-	nlmsg_free(msg);
 	return 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 @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 	return ret;
 }
 
-int mptcp_userspace_pm_get_addr(u8 id, struct genl_info *info)
+int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+				struct genl_info *info)
 {
 	struct mptcp_pm_addr_entry *entry;
 	struct mptcp_sock *msk;
-	struct sk_buff *msg;
 	int ret = -EINVAL;
 	struct sock *sk;
-	void *reply;
 
 	msk = mptcp_userspace_pm_get_sock(info);
 	if (!msk)
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_addr(u8 id, struct genl_info *info)
 
 	sk = (struct sock *)msk;
 
-	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-	if (!msg) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
-				  info->genlhdr->cmd);
-	if (!reply) {
-		GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
-		ret = -EMSGSIZE;
-		goto fail;
-	}
-
 	lock_sock(sk);
 	spin_lock_bh(&msk->pm.lock);
 	entry = mptcp_userspace_pm_lookup_addr_by_id(msk, id);
-	if (!entry) {
-		GENL_SET_ERR_MSG(info, "address not found");
-		ret = -EINVAL;
-		goto unlock_fail;
+	if (entry) {
+		*addr = *entry;
+		ret = 0;
 	}
-
-	ret = mptcp_nl_fill_addr(msg, entry);
-	if (ret)
-		goto unlock_fail;
-
-	genlmsg_end(msg, reply);
-	ret = genlmsg_reply(msg, info);
 	spin_unlock_bh(&msk->pm.lock);
 	release_sock(sk);
-	sock_put(sk);
-	return ret;
 
-unlock_fail:
-	spin_unlock_bh(&msk->pm.lock);
-	release_sock(sk);
-fail:
-	nlmsg_free(msg);
-out:
 	sock_put(sk);
 	return ret;
 }
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_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb);
 int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 				 struct netlink_callback *cb);
-int mptcp_pm_nl_get_addr(u8 id, struct genl_info *info);
-int mptcp_userspace_pm_get_addr(u8 id, struct genl_info *info);
+int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+			 struct genl_info *info);
+int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+				struct genl_info *info);
 
 static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflow)
 {
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

get_addr() interfaces will be invoked by dump_addr(), which using const
parameters "info", so this patch changes "info" parameters of get_addr()
as const too.

Some adaptations are also needed. No longer use genl_info_pm_nl() because
it doesn't accept a 'const' variable, but that's OK to get pernet via
genl_info_net().

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 2 +-
 net/mptcp/pm_netlink.c   | 7 +++++--
 net/mptcp/pm_userspace.c | 2 +-
 net/mptcp/protocol.h     | 4 ++--
 4 files changed, 9 insertions(+), 6 deletions(-)

From: Geliang Tang <tanggeliang@kylinos.cn>

The genl_info information is useful for dump_addr() interface in both
in-kernel PM and userspace PM. The former can use it to get pm_nl_pernet,
the latter can use it to get msk through mptcp_userspace_pm_get_sock().

So this patch adds an "info" parameter to dump_addr interface, so that
"info" can be obtained in mptcp_pm_nl_get_addr_dumpit() and then passed to
mptcp_pm_nl_dump_addr() or mptcp_userspace_pm_dump_addr(), without having
to get it again in these two functions.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 13 +++++++------
 net/mptcp/pm_netlink.c   |  5 +++--
 net/mptcp/pm_userspace.c |  4 ++--
 net/mptcp/protocol.h     |  6 ++++--
 4 files changed, 16 insertions(+), 12 deletions(-)

From: Geliang Tang <tanggeliang@kylinos.cn>

A new type mptcp_pm_addr_id_bitmap_t is defined to easily modify
dump_addr() interface of the path managers to accept an id_bitmap
type parameter. It also allows this parameter of dump_addr() can
be modified by BPF program when implementing this interface of a
BFP path manager.

With the help of get_addr(), we can modify dump_addr() interfaces
to reuse send_nlmsg code between the netlink PM and userspace PM.

The current dump_addr() flow looks like this:

lock();
	for_each_entry(entry)
		send_nlmsg(entry);
	unlock();

After holding the lock, get every entry by walking the address list,
send each one looply, and finally release the lock.

This set changes the process by copying the address list to an id
bitmap while holding the lock, then release the lock immediately.
After that, without locking, walking the copied id bitmap to get
every copy of entry by using get_addr(), and send each one looply:

lock();
	for_each_entry(entry)
		set_bit(bitmap);
	unlock();

for_each_bit(bitmap) {
		copy = get_addr();
		send_nlmsg(copy);
	}

With this, we can reuse the send_nlmsg() code in dump_addr() interfaces
between the netlink PM and userspace PM. They only need to implement
their own dump_addr() interfaces to hold the different locks, copy the
different address lists to an id bitmap, then release the locks.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 include/net/mptcp.h      |  7 +++++++
 net/mptcp/pm.c           | 42 +++++++++++++++++++++++++++++++++++----
 net/mptcp/pm_netlink.c   | 35 +++-----------------------------
 net/mptcp/pm_userspace.c | 43 ++++++++++++++--------------------------
 net/mptcp/protocol.h     |  9 ++-------
 5 files changed, 65 insertions(+), 71 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;
 
+/* max value of mptcp_addr_info.id */
+#define MPTCP_PM_MAX_ADDR_ID		U8_MAX
+
+typedef struct {
+	DECLARE_BITMAP(map, MPTCP_PM_MAX_ADDR_ID + 1);
+} mptcp_pm_addr_id_bitmap_t;
+
 #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 @@ int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-static int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb,
+static int mptcp_pm_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
 			      const struct genl_info *info)
 {
 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
-		return mptcp_userspace_pm_dump_addr(msg, cb, info);
-	return mptcp_pm_nl_dump_addr(msg, cb, info);
+		return mptcp_userspace_pm_dump_addr(bitmap, info);
+	return mptcp_pm_nl_dump_addr(bitmap, info);
 }
 
 int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
 				struct netlink_callback *cb)
 {
 	const struct genl_info *info = genl_info_dump(cb);
+	mptcp_pm_addr_id_bitmap_t *bitmap;
+	struct mptcp_pm_addr_entry entry;
+	int id = cb->args[0];
+	void *hdr;
+	int i;
 
-	return mptcp_pm_dump_addr(msg, cb, info);
+	bitmap = (mptcp_pm_addr_id_bitmap_t *)cb->ctx;
+
+	mptcp_pm_dump_addr(bitmap, info);
+
+	for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
+		if (test_bit(i, bitmap->map)) {
+			if (mptcp_pm_get_addr(i, &entry, info))
+				break;
+
+			if (id && entry.addr.id <= id)
+				continue;
+
+			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, &mptcp_genl_family,
+					  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
+			if (!hdr)
+				break;
+
+			if (mptcp_nl_fill_addr(msg, &entry) < 0) {
+				genlmsg_cancel(msg, hdr);
+				break;
+			}
+
+			id = entry.addr.id;
+			genlmsg_end(msg, hdr);
+		}
+	}
+
+	cb->args[0] = id;
+	return msg->len;
 }
 
 static int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
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_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 	return ret;
 }
 
-int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
-			  struct netlink_callback *cb,
+int mptcp_pm_nl_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
 			  const struct genl_info *info)
 {
 	struct net *net = genl_info_net(info);
-	struct mptcp_pm_addr_entry *entry;
 	struct pm_nl_pernet *pernet;
-	int id = cb->args[0];
-	void *hdr;
-	int i;
 
 	pernet = pm_nl_get_pernet(net);
 
 	rcu_read_lock();
-	for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
-		if (test_bit(i, pernet->id_bitmap)) {
-			entry = __lookup_addr_by_id(pernet, i);
-			if (!entry)
-				break;
-
-			if (entry->addr.id <= id)
-				continue;
-
-			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
-					  cb->nlh->nlmsg_seq, &mptcp_genl_family,
-					  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
-			if (!hdr)
-				break;
-
-			if (mptcp_nl_fill_addr(msg, entry) < 0) {
-				genlmsg_cancel(msg, hdr);
-				break;
-			}
-
-			id = entry->addr.id;
-			genlmsg_end(msg, hdr);
-		}
-	}
+	bitmap_copy(bitmap->map, pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
 	rcu_read_unlock();
 
-	cb->args[0] = id;
-	return msg->len;
+	return 0;
 }
 
 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
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_set_flags(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
-				 struct netlink_callback *cb,
-				 const struct genl_info *info)
+static int mptcp_userspace_pm_reset_bitmap(struct mptcp_sock *msk,
+					   mptcp_pm_addr_id_bitmap_t *bitmap)
 {
-	struct id_bitmap {
-		DECLARE_BITMAP(map, MPTCP_PM_MAX_ADDR_ID + 1);
-	} *bitmap;
 	struct mptcp_pm_addr_entry *entry;
+
+	bitmap_zero(bitmap->map, MPTCP_PM_MAX_ADDR_ID + 1);
+
+	mptcp_for_each_userspace_pm_addr(msk, entry)
+		__set_bit(entry->addr.id, bitmap->map);
+
+	return 0;
+}
+
+int mptcp_userspace_pm_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
+				 const struct genl_info *info)
+{
 	struct mptcp_sock *msk;
 	int ret = -EINVAL;
 	struct sock *sk;
-	void *hdr;
-
-	bitmap = (struct id_bitmap *)cb->ctx;
 
 	msk = mptcp_userspace_pm_get_sock(info);
 	if (!msk)
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 
 	lock_sock(sk);
 	spin_lock_bh(&msk->pm.lock);
-	mptcp_for_each_userspace_pm_addr(msk, entry) {
-		if (test_bit(entry->addr.id, bitmap->map))
-			continue;
-
-		hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
-				  cb->nlh->nlmsg_seq, &mptcp_genl_family,
-				  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
-		if (!hdr)
-			break;
-
-		if (mptcp_nl_fill_addr(msg, entry) < 0) {
-			genlmsg_cancel(msg, hdr);
-			break;
-		}
-
-		__set_bit(entry->addr.id, bitmap->map);
-		genlmsg_end(msg, hdr);
-	}
+	ret = mptcp_userspace_pm_reset_bitmap(msk, bitmap);
 	spin_unlock_bh(&msk->pm.lock);
 	release_sock(sk);
-	ret = msg->len;
 
 	sock_put(sk);
 	return ret;
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 @@ enum mptcp_addr_signal_status {
 	MPTCP_RM_ADDR_SIGNAL,
 };
 
-/* max value of mptcp_addr_info.id */
-#define MPTCP_PM_MAX_ADDR_ID		U8_MAX
-
 struct mptcp_pm_data {
 	struct mptcp_addr_info local;
 	struct mptcp_addr_info remote;
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_in
 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_pm_nl_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
 			  const struct genl_info *info);
-int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
-				 struct netlink_callback *cb,
+int mptcp_userspace_pm_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
 				 const struct genl_info *info);
 int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 			 const struct genl_info *info);
-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

v2:
 - split patch 7 of v1 into two.
 - patches 1-6 have no code changes, only the commit logs have been
updated.
 - more commit log to explain why mptcp_pm_addr_id_bitmap_t needs to
be defined.
 - use mptcp_pm_addr_id_bitmap_t in userspace_pm_append_new_local_addr
too.

In order to implement BPF userspace path manager, it is necessary to
unify the interfaces of the path manager. This set updates get_addr()
and dump_addr() interfaces.

Geliang Tang (8):
  mptcp: make three pm wrappers static
  mptcp: drop skb parameter of get_addr
  mptcp: add id parameter for get_addr
  mptcp: reuse sending nlmsg code in get_addr
  mptcp: change info of get_addr as const
  mptcp: add info parameter for dump_addr
  mptcp: add mptcp_pm_addr_id_bitmap_t type
  mptcp: reuse sending nlmsg code in dump_addr

include/net/mptcp.h      |   7 +++
 net/mptcp/pm.c           | 108 ++++++++++++++++++++++++++++++++++++---
 net/mptcp/pm_netlink.c   | 105 ++++++-------------------------------
 net/mptcp/pm_userspace.c | 102 ++++++++++--------------------------
 net/mptcp/protocol.h     |  21 +++-----
 5 files changed, 157 insertions(+), 186 deletions(-)

-- 
2.45.2

From: Geliang Tang <tanggeliang@kylinos.cn>

With the help of get_addr(), we can modify dump_addr() interfaces
to reuse send_nlmsg code between the netlink PM and userspace PM.

The current dump_addr() flow looks like this:

lock();
	for_each_entry(entry)
		send_nlmsg(entry);
	unlock();

After holding the lock, get every entry by walking the address list,
send each one looply, and finally release the lock.

lock();
	for_each_entry(entry)
		set_bit(bitmap);
	unlock();

for_each_bit(bitmap) {
		copy = get_addr();
		send_nlmsg(copy);
	}

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm.c           | 43 ++++++++++++++++++++++++++++++++++++----
 net/mptcp/pm_netlink.c   | 35 +++-----------------------------
 net/mptcp/pm_userspace.c | 41 ++++++++++++++------------------------
 net/mptcp/protocol.h     |  6 ++----
 4 files changed, 59 insertions(+), 66 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_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-static int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb,
+static int mptcp_pm_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
 			      const struct genl_info *info)
 {
 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
-		return mptcp_userspace_pm_dump_addr(msg, cb, info);
-	return mptcp_pm_nl_dump_addr(msg, cb, info);
+		return mptcp_userspace_pm_dump_addr(bitmap, info);
+	return mptcp_pm_nl_dump_addr(bitmap, info);
 }
 
 int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
 				struct netlink_callback *cb)
 {
 	const struct genl_info *info = genl_info_dump(cb);
+	mptcp_pm_addr_id_bitmap_t *bitmap;
+	struct mptcp_pm_addr_entry entry;
+	int id = cb->args[0];
+	void *hdr;
+	int i;
+
+	bitmap = (mptcp_pm_addr_id_bitmap_t *)cb->ctx;
+
+	mptcp_pm_dump_addr(bitmap, info);
+
+	for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
+		if (test_bit(i, bitmap->map)) {
+			if (mptcp_pm_get_addr(i, &entry, info))
+				break;
+
+			if (id && entry.addr.id <= id)
+				continue;
+
+			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq,
+					  &mptcp_genl_family, NLM_F_MULTI,
+					  MPTCP_PM_CMD_GET_ADDR);
+			if (!hdr)
+				break;
+
+			if (mptcp_nl_fill_addr(msg, &entry) < 0) {
+				genlmsg_cancel(msg, hdr);
+				break;
+			}
+
+			id = entry.addr.id;
+			genlmsg_end(msg, hdr);
+		}
+	}
 
-	return mptcp_pm_dump_addr(msg, cb, info);
+	cb->args[0] = id;
+	return msg->len;
 }
 
 static int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
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_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 	return ret;
 }
 
-int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
-			  struct netlink_callback *cb,
+int mptcp_pm_nl_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
 			  const struct genl_info *info)
 {
 	struct net *net = genl_info_net(info);
-	struct mptcp_pm_addr_entry *entry;
 	struct pm_nl_pernet *pernet;
-	int id = cb->args[0];
-	void *hdr;
-	int i;
 
 	pernet = pm_nl_get_pernet(net);
 
 	rcu_read_lock();
-	for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
-		if (test_bit(i, pernet->id_bitmap)) {
-			entry = __lookup_addr_by_id(pernet, i);
-			if (!entry)
-				break;
-
-			if (entry->addr.id <= id)
-				continue;
-
-			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
-					  cb->nlh->nlmsg_seq, &mptcp_genl_family,
-					  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
-			if (!hdr)
-				break;
-
-			if (mptcp_nl_fill_addr(msg, entry) < 0) {
-				genlmsg_cancel(msg, hdr);
-				break;
-			}
-
-			id = entry->addr.id;
-			genlmsg_end(msg, hdr);
-		}
-	}
+	bitmap_copy(bitmap->map, pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
 	rcu_read_unlock();
 
-	cb->args[0] = id;
-	return msg->len;
+	return 0;
 }
 
 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
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_set_flags(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
-				 struct netlink_callback *cb,
-				 const struct genl_info *info)
+static int mptcp_userspace_pm_reset_bitmap(struct mptcp_sock *msk,
+					   mptcp_pm_addr_id_bitmap_t *bitmap)
 {
-	mptcp_pm_addr_id_bitmap_t *bitmap;
 	struct mptcp_pm_addr_entry *entry;
+
+	bitmap_zero(bitmap->map, MPTCP_PM_MAX_ADDR_ID + 1);
+
+	mptcp_for_each_userspace_pm_addr(msk, entry)
+		__set_bit(entry->addr.id, bitmap->map);
+
+	return 0;
+}
+
+int mptcp_userspace_pm_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
+				 const struct genl_info *info)
+{
 	struct mptcp_sock *msk;
 	int ret = -EINVAL;
 	struct sock *sk;
-	void *hdr;
-
-	bitmap = (mptcp_pm_addr_id_bitmap_t *)cb->ctx;
 
 	msk = mptcp_userspace_pm_get_sock(info);
 	if (!msk)
@@ -XXX,XX +XXX,XX @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 
 	lock_sock(sk);
 	spin_lock_bh(&msk->pm.lock);
-	mptcp_for_each_userspace_pm_addr(msk, entry) {
-		if (test_bit(entry->addr.id, bitmap->map))
-			continue;
-
-		hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
-				  cb->nlh->nlmsg_seq, &mptcp_genl_family,
-				  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
-		if (!hdr)
-			break;
-
-		if (mptcp_nl_fill_addr(msg, entry) < 0) {
-			genlmsg_cancel(msg, hdr);
-			break;
-		}
-
-		__set_bit(entry->addr.id, bitmap->map);
-		genlmsg_end(msg, hdr);
-	}
+	ret = mptcp_userspace_pm_reset_bitmap(msk, bitmap);
 	spin_unlock_bh(&msk->pm.lock);
 	release_sock(sk);
-	ret = msg->len;
 
 	sock_put(sk);
 	return ret;
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_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_in
 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_pm_nl_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
 			  const struct genl_info *info);
-int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
-				 struct netlink_callback *cb,
+int mptcp_userspace_pm_dump_addr(mptcp_pm_addr_id_bitmap_t *bitmap,
 				 const struct genl_info *info);
 int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 			 const struct genl_info *info);
-- 
2.45.2