mptcp: allow changing the "backup" bit by endpoint id

a non-zero 'id' is sufficient to identify MPTCP endpoints: allow changing
the value of 'backup' bit by simply specifying the endpoint id.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/158
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 7b96be1e9f14a11ddcfe41f609fdc1730e33106e..4ff8d55cbe822ff5e7923a45a15b4b1f6acc39d7 100644 (file)
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1702,22 +1702,28 @@ next:
 
 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
 {
+       struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, }, *entry;
        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;
+       u8 bkup = 0, lookup_by_id = 0;
        int ret;
 
-       ret = mptcp_pm_parse_addr(attr, info, true, &addr);
+       ret = mptcp_pm_parse_addr(attr, info, false, &addr);
        if (ret < 0)
                return ret;
 
        if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
                bkup = 1;
+       if (addr.addr.family == AF_UNSPEC) {
+               lookup_by_id = 1;
+               if (!addr.addr.id)
+                       return -EOPNOTSUPP;
+       }
 
        list_for_each_entry(entry, &pernet->local_addr_list, list) {
-               if (addresses_equal(&entry->addr, &addr.addr, true)) {
+               if ((!lookup_by_id && addresses_equal(&entry->addr, &addr.addr, true)) ||
+                   (lookup_by_id && entry->addr.id == addr.addr.id)) {
                        mptcp_nl_addr_backup(net, &entry->addr, bkup);
 
                        if (bkup)