phonet: Don't hold RTNL for addr_doit().

Now only __dev_get_by_index() depends on RTNL in addr_doit().

Let's use dev_get_by_index_rcu() and register addr_doit() with
RTNL_FLAG_DOIT_UNLOCKED.

While at it, I changed phonet_rtnl_msg_handlers[]'s init to C99
style like other core networking code.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c
index 23097085ad38e22240e3700ea1a4eba2c8cc2c21..5996141e258fb7edd620be0eb12ee2970c73e88d 100644 (file)
--- a/net/phonet/pn_netlink.c
+++ b/net/phonet/pn_netlink.c
@@ -65,8 +65,6 @@ static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
        if (!netlink_capable(skb, CAP_SYS_ADMIN))
                return -EPERM;
 
-       ASSERT_RTNL();
-
        err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
                                     ifa_phonet_policy, extack);
        if (err < 0)
@@ -80,16 +78,24 @@ static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
                /* Phonet addresses only have 6 high-order bits */
                return -EINVAL;
 
-       dev = __dev_get_by_index(net, ifm->ifa_index);
-       if (dev == NULL)
+       rcu_read_lock();
+
+       dev = dev_get_by_index_rcu(net, ifm->ifa_index);
+       if (!dev) {
+               rcu_read_unlock();
                return -ENODEV;
+       }
 
        if (nlh->nlmsg_type == RTM_NEWADDR)
                err = phonet_address_add(dev, pnaddr);
        else
                err = phonet_address_del(dev, pnaddr);
+
+       rcu_read_unlock();
+
        if (!err)
                phonet_address_notify(net, nlh->nlmsg_type, ifm->ifa_index, pnaddr);
+
        return err;
 }
 
@@ -287,13 +293,18 @@ static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 }
 
 static const struct rtnl_msg_handler phonet_rtnl_msg_handlers[] __initdata_or_module = {
-       {THIS_MODULE, PF_PHONET, RTM_NEWADDR, addr_doit, NULL, 0},
-       {THIS_MODULE, PF_PHONET, RTM_DELADDR, addr_doit, NULL, 0},
-       {THIS_MODULE, PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit, 0},
-       {THIS_MODULE, PF_PHONET, RTM_NEWROUTE, route_doit, NULL, 0},
-       {THIS_MODULE, PF_PHONET, RTM_DELROUTE, route_doit, NULL, 0},
-       {THIS_MODULE, PF_PHONET, RTM_GETROUTE, NULL, route_dumpit,
-        RTNL_FLAG_DUMP_UNLOCKED},
+       {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_NEWADDR,
+        .doit = addr_doit, .flags = RTNL_FLAG_DOIT_UNLOCKED},
+       {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_DELADDR,
+        .doit = addr_doit, .flags = RTNL_FLAG_DOIT_UNLOCKED},
+       {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_GETADDR,
+        .dumpit = getaddr_dumpit},
+       {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_NEWROUTE,
+        .doit = route_doit},
+       {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_DELROUTE,
+        .doit = route_doit},
+       {.owner = THIS_MODULE, .protocol = PF_PHONET, .msgtype = RTM_GETROUTE,
+        .dumpit = route_dumpit, .flags = RTNL_FLAG_DUMP_UNLOCKED},
 };
 
 int __init phonet_netlink_register(void)