mptcp: retransmit ADD_ADDR when timeout

This patch implemented the retransmition of ADD_ADDR when no ADD_ADDR echo
is received. It added a timer with the announced address. When timeout
occurs, ADD_ADDR will be retransmitted.

Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 171039c..14a290f 100644 (file)
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -893,6 +893,7 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb,
                        mptcp_pm_add_addr_received(msk, &addr);
                        MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR);
                } else {
+                       mptcp_pm_del_add_timer(msk, &addr);
                        MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD);
                }
                mp_opt.add_addr = 0;

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 701972b..5a0e4d1 100644 (file)
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -31,6 +31,9 @@ struct mptcp_pm_addr_entry {
 struct mptcp_pm_add_entry {
        struct list_head        list;
        struct mptcp_addr_info  addr;
+       struct timer_list       add_timer;
+       struct mptcp_sock       *sock;
+       u8                      retrans_times;
 };
 
 struct pm_nl_pernet {
@@ -46,6 +49,7 @@ struct pm_nl_pernet {
 };
 
 #define MPTCP_PM_ADDR_MAX      8
+#define ADD_ADDR_RETRANS_MAX   3
 
 static bool addresses_equal(const struct mptcp_addr_info *a,
                            struct mptcp_addr_info *b, bool use_port)
@@ -183,23 +187,83 @@ static void check_work_pending(struct mptcp_sock *msk)
                WRITE_ONCE(msk->pm.work_pending, false);
 }
 
-static bool lookup_anno_list_by_saddr(struct mptcp_sock *msk,
-                                     struct mptcp_addr_info *addr)
+static struct mptcp_pm_add_entry *
+lookup_anno_list_by_saddr(struct mptcp_sock *msk,
+                         struct mptcp_addr_info *addr)
 {
        struct mptcp_pm_add_entry *entry;
 
        list_for_each_entry(entry, &msk->pm.anno_list, list) {
                if (addresses_equal(&entry->addr, addr, false))
-                       return true;
+                       return entry;
        }
 
-       return false;
+       return NULL;
+}
+
+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;
+
+       pr_debug("msk=%p", msk);
+
+       if (!msk)
+               return;
+
+       if (inet_sk_state_load(sk) == TCP_CLOSE)
+               return;
+
+       if (!entry->addr.id)
+               return;
+
+       if (mptcp_pm_should_add_signal(msk)) {
+               sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
+               goto out;
+       }
+
+       spin_lock_bh(&msk->pm.lock);
+
+       if (!mptcp_pm_should_add_signal(msk)) {
+               pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
+               mptcp_pm_announce_addr(msk, &entry->addr, false);
+               entry->retrans_times++;
+       }
+
+       if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
+               sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX);
+
+       spin_unlock_bh(&msk->pm.lock);
+
+out:
+       __sock_put(sk);
+}
+
+struct mptcp_pm_add_entry *
+mptcp_pm_del_add_timer(struct mptcp_sock *msk,
+                      struct mptcp_addr_info *addr)
+{
+       struct mptcp_pm_add_entry *entry;
+       struct sock *sk = (struct sock *)msk;
+
+       spin_lock_bh(&msk->pm.lock);
+       entry = lookup_anno_list_by_saddr(msk, addr);
+       if (entry)
+               entry->retrans_times = ADD_ADDR_RETRANS_MAX;
+       spin_unlock_bh(&msk->pm.lock);
+
+       if (entry)
+               sk_stop_timer_sync(sk, &entry->add_timer);
+
+       return entry;
 }
 
 static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
                                     struct mptcp_pm_addr_entry *entry)
 {
        struct mptcp_pm_add_entry *add_entry = NULL;
+       struct sock *sk = (struct sock *)msk;
 
        if (lookup_anno_list_by_saddr(msk, &entry->addr))
                return false;
@@ -210,21 +274,32 @@ static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 
        list_add(&add_entry->list, &msk->pm.anno_list);
 
+       add_entry->addr = entry->addr;
+       add_entry->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);
+
        return true;
 }
 
 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
 {
        struct mptcp_pm_add_entry *entry, *tmp;
+       struct sock *sk = (struct sock *)msk;
+       LIST_HEAD(free_list);
 
        pr_debug("msk=%p", msk);
 
        spin_lock_bh(&msk->pm.lock);
-       list_for_each_entry_safe(entry, tmp, &msk->pm.anno_list, list) {
-               list_del(&entry->list);
+       list_splice_init(&msk->pm.anno_list, &free_list);
+       spin_unlock_bh(&msk->pm.lock);
+
+       list_for_each_entry_safe(entry, tmp, &free_list, list) {
+               sk_stop_timer_sync(sk, &entry->add_timer);
                kfree(entry);
        }
-       spin_unlock_bh(&msk->pm.lock);
 }
 
 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
@@ -659,14 +734,13 @@ __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
                                      struct mptcp_addr_info *addr)
 {
-       struct mptcp_pm_add_entry *entry, *tmp;
+       struct mptcp_pm_add_entry *entry;
 
-       list_for_each_entry_safe(entry, tmp, &msk->pm.anno_list, list) {
-               if (addresses_equal(&entry->addr, addr, false)) {
-                       list_del(&entry->list);
-                       kfree(entry);
-                       return true;
-               }
+       entry = mptcp_pm_del_add_timer(msk, addr);
+       if (entry) {
+               list_del(&entry->list);
+               kfree(entry);
+               return true;
        }
 
        return false;
@@ -678,11 +752,12 @@ static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
 {
        bool ret;
 
-       spin_lock_bh(&msk->pm.lock);
        ret = remove_anno_list_by_saddr(msk, addr);
-       if (ret || force)
+       if (ret || force) {
+               spin_lock_bh(&msk->pm.lock);
                mptcp_pm_remove_addr(msk, addr->id);
-       spin_unlock_bh(&msk->pm.lock);
+               spin_unlock_bh(&msk->pm.lock);
+       }
        return ret;
 }
 

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index db1e5de..7cfe52a 100644 (file)
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -444,6 +444,9 @@ 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);
 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
+struct mptcp_pm_add_entry *
+mptcp_pm_del_add_timer(struct mptcp_sock *msk,
+                      struct mptcp_addr_info *addr);
 
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
                           const struct mptcp_addr_info *addr,