mptcp: add set_flags command in PM netlink

This patch added a new command MPTCP_PM_CMD_SET_FLAGS in PM netlink:

In mptcp_nl_cmd_set_flags, parse the input address, get the backup value
according to whether the address's FLAG_BACKUP flag is set from the
user-space. Then check whether this address had been added in the local
address list. If it had been, then call mptcp_nl_addr_backup to deal with
this address.

In mptcp_nl_addr_backup, traverse all the existing msk sockets to find
the relevant sockets, and call mptcp_pm_nl_mp_prio_send_ack to send out
a MP_PRIO ACK packet.

Finally in mptcp_nl_cmd_set_flags, set or clear the address's FLAG_BACKUP
flag.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index 9762660..3674a45 100644 (file)
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -82,6 +82,7 @@ enum {
        MPTCP_PM_CMD_FLUSH_ADDRS,
        MPTCP_PM_CMD_SET_LIMITS,
        MPTCP_PM_CMD_GET_LIMITS,
+       MPTCP_PM_CMD_SET_FLAGS,
 
        __MPTCP_PM_CMD_AFTER_LAST
 };

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index bf0d13c..8f80099 100644 (file)
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1164,6 +1164,66 @@ fail:
        return -EMSGSIZE;
 }
 
+static int mptcp_nl_addr_backup(struct net *net,
+                               struct mptcp_addr_info *addr,
+                               u8 bkup)
+{
+       long s_slot = 0, s_num = 0;
+       struct mptcp_sock *msk;
+       int ret = -EINVAL;
+
+       while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
+               struct sock *sk = (struct sock *)msk;
+
+               if (list_empty(&msk->conn_list))
+                       goto next;
+
+               lock_sock(sk);
+               spin_lock_bh(&msk->pm.lock);
+               ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
+               spin_unlock_bh(&msk->pm.lock);
+               release_sock(sk);
+
+next:
+               sock_put(sk);
+               cond_resched();
+       }
+
+       return ret;
+}
+
+static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
+{
+       struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+       struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
+       struct mptcp_pm_addr_entry addr, *entry;
+       struct net *net = sock_net(skb->sk);
+       u8 bkup = 0;
+       int ret;
+
+       ret = mptcp_pm_parse_addr(attr, info, true, &addr);
+       if (ret < 0)
+               return ret;
+
+       if (addr.addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
+               bkup = 1;
+
+       list_for_each_entry(entry, &pernet->local_addr_list, list) {
+               if (addresses_equal(&entry->addr, &addr.addr, true)) {
+                       ret = mptcp_nl_addr_backup(net, &entry->addr, bkup);
+                       if (ret)
+                               return ret;
+
+                       if (bkup)
+                               entry->addr.flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
+                       else
+                               entry->addr.flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
+               }
+       }
+
+       return 0;
+}
+
 static const struct genl_small_ops mptcp_pm_ops[] = {
        {
                .cmd    = MPTCP_PM_CMD_ADD_ADDR,
@@ -1194,6 +1254,11 @@ static const struct genl_small_ops mptcp_pm_ops[] = {
                .cmd    = MPTCP_PM_CMD_GET_LIMITS,
                .doit   = mptcp_nl_cmd_get_limits,
        },
+       {
+               .cmd    = MPTCP_PM_CMD_SET_FLAGS,
+               .doit   = mptcp_nl_cmd_set_flags,
+               .flags  = GENL_ADMIN_PERM,
+       },
 };
 
 static struct genl_family mptcp_genl_family __ro_after_init = {