[PATCH net-next 5/6] mptcp: add a new sysctl add_addr_timeout

[Mat Martineau]

From: Geliang Tang <geliangt...@gmail.com>

This patch added a new sysctl, named add_addr_timeout, to control the
timeout value (in seconds) of the ADD_ADDR retransmission.

Suggested-by: Matthieu Baerts <matthieu.bae...@tessares.net>
Suggested-by: Paolo Abeni <pab...@redhat.com>
Acked-by: Paolo Abeni <pab...@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.bae...@tessares.net>
Signed-off-by: Geliang Tang <geliangt...@gmail.com>
---
 net/mptcp/ctrl.c       | 14 ++++++++++++++
 net/mptcp/pm_netlink.c |  8 ++++++--
 net/mptcp/protocol.h   |  1 +
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
index 54b888f94009..96ba616f59bf 100644
--- a/net/mptcp/ctrl.c
+++ b/net/mptcp/ctrl.c
@@ -18,6 +18,7 @@ struct mptcp_pernet {
        struct ctl_table_header *ctl_table_hdr;
 
        int mptcp_enabled;
+       unsigned int add_addr_timeout;
 };
 
 static struct mptcp_pernet *mptcp_get_pernet(struct net *net)
@@ -30,6 +31,11 @@ int mptcp_is_enabled(struct net *net)
        return mptcp_get_pernet(net)->mptcp_enabled;
 }
 
+unsigned int mptcp_get_add_addr_timeout(struct net *net)
+{
+       return mptcp_get_pernet(net)->add_addr_timeout;
+}
+
 static struct ctl_table mptcp_sysctl_table[] = {
        {
                .procname = "enabled",
@@ -40,12 +46,19 @@ static struct ctl_table mptcp_sysctl_table[] = {
                 */
                .proc_handler = proc_dointvec,
        },
+       {
+               .procname = "add_addr_timeout",
+               .maxlen = sizeof(unsigned int),
+               .mode = 0644,
+               .proc_handler = proc_dointvec_jiffies,
+       },
        {}
 };
 
 static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
 {
        pernet->mptcp_enabled = 1;
+       pernet->add_addr_timeout = TCP_RTO_MAX;
 }
 
 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
@@ -61,6 +74,7 @@ static int mptcp_pernet_new_table(struct net *net, struct 
mptcp_pernet *pernet)
        }
 
        table[0].data = &pernet->mptcp_enabled;
+       table[1].data = &pernet->add_addr_timeout;
 
        hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);
        if (!hdr)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 0d6f3d912891..ed60538df7b2 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -206,6 +206,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
        struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
        struct mptcp_sock *msk = entry->sock;
        struct sock *sk = (struct sock *)msk;
+       struct net *net = sock_net(sk);
 
        pr_debug("msk=%p", msk);
 
@@ -232,7 +233,8 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
        }
 
        if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
-               sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX);
+               sk_reset_timer(sk, timer,
+                              jiffies + mptcp_get_add_addr_timeout(net));
 
        spin_unlock_bh(&msk->pm.lock);
 
@@ -264,6 +266,7 @@ static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 {
        struct mptcp_pm_add_entry *add_entry = NULL;
        struct sock *sk = (struct sock *)msk;
+       struct net *net = sock_net(sk);
 
        if (lookup_anno_list_by_saddr(msk, &entry->addr))
                return false;
@@ -279,7 +282,8 @@ static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
        add_entry->retrans_times = 0;
 
        timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
-       sk_reset_timer(sk, &add_entry->add_timer, jiffies + TCP_RTO_MAX);
+       sk_reset_timer(sk, &add_entry->add_timer,
+                      jiffies + mptcp_get_add_addr_timeout(net));
 
        return true;
 }
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 13ab89dc1914..278c88c405e8 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -362,6 +362,7 @@ mptcp_subflow_get_mapped_dsn(const struct 
mptcp_subflow_context *subflow)
 }
 
 int mptcp_is_enabled(struct net *net);
+unsigned int mptcp_get_add_addr_timeout(struct net *net);
 void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,
                                     struct mptcp_options_received *mp_opt);
 bool mptcp_subflow_data_available(struct sock *sk);
-- 
2.29.2