[MPTCP][PATCH net-next 03/16] mptcp: add the incoming RM_ADDR support

From: Geliang Tang
Date: Wed Sep 23 2020 - 20:39:05 EST


This patch added the RM_ADDR option parsing logic:

We parsed the incoming options to find if the rm_addr option is received,
and called mptcp_pm_rm_addr_received to schedule PM work to a new status,
named MPTCP_PM_RM_ADDR_RECEIVED.

PM work got this status, and called mptcp_pm_nl_rm_addr_received to handle
it.

In mptcp_pm_nl_rm_addr_received, we closed the subflow matching the rm_id,
and updated PM counter.

Suggested-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Suggested-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Suggested-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
Signed-off-by: Geliang Tang <geliangtang@xxxxxxxxx>
---
net/mptcp/options.c | 5 +++++
net/mptcp/pm.c | 12 ++++++++++++
net/mptcp/pm_netlink.c | 34 ++++++++++++++++++++++++++++++++++
net/mptcp/protocol.c | 12 ++++++++----
net/mptcp/protocol.h | 7 +++++++
5 files changed, 66 insertions(+), 4 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index bbc124876417..a52a05effac9 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -888,6 +888,11 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb,
mp_opt.add_addr = 0;
}

+ if (mp_opt.rm_addr) {
+ mptcp_pm_rm_addr_received(msk, mp_opt.rm_id);
+ mp_opt.rm_addr = 0;
+ }
+
if (!mp_opt.dss)
return;

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 81b07ae213b9..558462d87eb3 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -149,6 +149,18 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
spin_unlock_bh(&pm->lock);
}

+void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id)
+{
+ struct mptcp_pm_data *pm = &msk->pm;
+
+ pr_debug("msk=%p remote_id=%d", msk, rm_id);
+
+ spin_lock_bh(&pm->lock);
+ mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED);
+ pm->rm_id = rm_id;
+ spin_unlock_bh(&pm->lock);
+}
+
/* path manager helpers */

bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index b4a9624d7bf2..4124bc581308 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -268,6 +268,40 @@ void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
spin_lock_bh(&msk->pm.lock);
}

+void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
+{
+ struct mptcp_subflow_context *subflow, *tmp;
+ struct sock *sk = (struct sock *)msk;
+
+ pr_debug("address rm_id %d", msk->pm.rm_id);
+
+ if (!msk->pm.rm_id)
+ return;
+
+ if (list_empty(&msk->conn_list))
+ return;
+
+ list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
+ struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+ int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
+ long timeout = 0;
+
+ if (msk->pm.rm_id != subflow->remote_id)
+ continue;
+
+ spin_unlock_bh(&msk->pm.lock);
+ mptcp_subflow_shutdown(sk, ssk, how);
+ __mptcp_close_ssk(sk, ssk, subflow, timeout);
+ spin_lock_bh(&msk->pm.lock);
+
+ msk->pm.add_addr_accepted--;
+ msk->pm.subflows--;
+ WRITE_ONCE(msk->pm.accept_addr, true);
+
+ break;
+ }
+}
+
static bool address_use_port(struct mptcp_pm_addr_entry *entry)
{
return (entry->addr.flags &
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 386cd4e60250..26b9233f247c 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1652,9 +1652,9 @@ static struct sock *mptcp_subflow_get_retrans(const struct mptcp_sock *msk)
* so we need to use tcp_close() after detaching them from the mptcp
* parent socket.
*/
-static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
- struct mptcp_subflow_context *subflow,
- long timeout)
+void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
+ struct mptcp_subflow_context *subflow,
+ long timeout)
{
struct socket *sock = READ_ONCE(ssk->sk_socket);

@@ -1685,6 +1685,10 @@ static void pm_work(struct mptcp_sock *msk)
pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
mptcp_pm_nl_add_addr_received(msk);
}
+ if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
+ pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
+ mptcp_pm_nl_rm_addr_received(msk);
+ }
if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
mptcp_pm_nl_fully_established(msk);
@@ -1846,7 +1850,7 @@ static void mptcp_cancel_work(struct sock *sk)
sock_put(sk);
}

-static void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
+void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
{
lock_sock(ssk);

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 8929b0c7660a..837e01057544 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -152,6 +152,7 @@ struct mptcp_addr_info {

enum mptcp_pm_status {
MPTCP_PM_ADD_ADDR_RECEIVED,
+ MPTCP_PM_RM_ADDR_RECEIVED,
MPTCP_PM_ESTABLISHED,
MPTCP_PM_SUBFLOW_ESTABLISHED,
};
@@ -362,6 +363,10 @@ void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
struct mptcp_options_received *mp_opt);
bool mptcp_subflow_data_available(struct sock *sk);
void __init mptcp_subflow_init(void);
+void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
+void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
+ struct mptcp_subflow_context *subflow,
+ long timeout);

/* called with sk socket lock held */
int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
@@ -434,6 +439,7 @@ void mptcp_pm_subflow_established(struct mptcp_sock *msk,
void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);
void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
const struct mptcp_addr_info *addr);
+void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id);

int mptcp_pm_announce_addr(struct mptcp_sock *msk,
const struct mptcp_addr_info *addr);
@@ -468,6 +474,7 @@ void mptcp_pm_nl_data_init(struct mptcp_sock *msk);
void mptcp_pm_nl_fully_established(struct mptcp_sock *msk);
void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk);
void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk);
+void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk);
int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);

static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)
--
2.17.1