mptcp: add address into userspace pm list

commit 24430f8bf51655c5ab7ddc2fafe939dd3cd0dd47 upstream.

Add the address into userspace_pm_local_addr_list when the subflow is
created. Make sure it can be found in mptcp_nl_cmd_remove(). And delete
it in the new helper mptcp_userspace_pm_delete_local_addr().

By doing this, the "REMOVE" command also works with subflows that have
been created via the "SUB_CREATE" command instead of restricting to
the addresses that have been announced via the "ANNOUNCE" command.

Fixes: d9a4594edabf ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE")
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/379
Cc: stable@vger.kernel.org
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index a0c1e32..7726e08 100644 (file)
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -78,6 +78,30 @@ int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
        return ret;
 }
 
+/* If the subflow is closed from the other peer (not via a
+ * subflow destroy command then), we want to keep the entry
+ * not to assign the same ID to another address and to be
+ * able to send RM_ADDR after the removal of the subflow.
+ */
+static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
+                                               struct mptcp_pm_addr_entry *addr)
+{
+       struct mptcp_pm_addr_entry *entry, *tmp;
+
+       list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
+               if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
+                       /* TODO: a refcount is needed because the entry can
+                        * be used multiple times (e.g. fullmesh mode).
+                        */
+                       list_del_rcu(&entry->list);
+                       kfree(entry);
+                       return 0;
+               }
+       }
+
+       return -EINVAL;
+}
+
 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
                                                   unsigned int id,
                                                   u8 *flags, int *ifindex)
@@ -250,6 +274,7 @@ int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
        struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
        struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
        struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
+       struct mptcp_pm_addr_entry local = { 0 };
        struct mptcp_addr_info addr_r;
        struct mptcp_addr_info addr_l;
        struct mptcp_sock *msk;
@@ -301,12 +326,24 @@ int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
                goto create_err;
        }
 
+       local.addr = addr_l;
+       err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
+       if (err < 0) {
+               GENL_SET_ERR_MSG(info, "did not match address and id");
+               goto create_err;
+       }
+
        lock_sock(sk);
 
        err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
 
        release_sock(sk);
 
+       spin_lock_bh(&msk->pm.lock);
+       if (err)
+               mptcp_userspace_pm_delete_local_addr(msk, &local);
+       spin_unlock_bh(&msk->pm.lock);
+
  create_err:
        sock_put((struct sock *)msk);
        return err;
@@ -419,7 +456,11 @@ int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
        ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
        if (ssk) {
                struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
+               struct mptcp_pm_addr_entry entry = { .addr = addr_l };
 
+               spin_lock_bh(&msk->pm.lock);
+               mptcp_userspace_pm_delete_local_addr(msk, &entry);
+               spin_unlock_bh(&msk->pm.lock);
                mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
                mptcp_close_ssk(sk, ssk, subflow);
                MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);