rtnetlink: Factorise do_setlink() path from __rtnl_newlink().

__rtnl_newlink() got too long to maintain.

For example, netdev_master_upper_dev_get()->rtnl_link_ops is fetched even
when IFLA_INFO_SLAVE_DATA is not specified.

Let's factorise the single dev do_setlink() path to a separate function.

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/core/rtnetlink.c b/net/core/rtnetlink.c
index 76593de7014c9b9697650428b0644ebbeabf057f..21165cc2b697433175003c8acd4698b2ba0e85db 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3505,6 +3505,78 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname,
 }
 EXPORT_SYMBOL(rtnl_create_link);
 
+struct rtnl_newlink_tbs {
+       struct nlattr *tb[IFLA_MAX + 1];
+       struct nlattr *linkinfo[IFLA_INFO_MAX + 1];
+       struct nlattr *attr[RTNL_MAX_TYPE + 1];
+       struct nlattr *slave_attr[RTNL_SLAVE_MAX_TYPE + 1];
+};
+
+static int rtnl_changelink(const struct sk_buff *skb, struct nlmsghdr *nlh,
+                          const struct rtnl_link_ops *ops,
+                          struct net_device *dev,
+                          struct rtnl_newlink_tbs *tbs,
+                          struct nlattr **data,
+                          struct netlink_ext_ack *extack)
+{
+       struct nlattr ** const linkinfo = tbs->linkinfo;
+       struct nlattr ** const tb = tbs->tb;
+       int status = 0;
+       int err;
+
+       if (nlh->nlmsg_flags & NLM_F_EXCL)
+               return -EEXIST;
+
+       if (nlh->nlmsg_flags & NLM_F_REPLACE)
+               return -EOPNOTSUPP;
+
+       if (linkinfo[IFLA_INFO_DATA]) {
+               if (!ops || ops != dev->rtnl_link_ops || !ops->changelink)
+                       return -EOPNOTSUPP;
+
+               err = ops->changelink(dev, tb, data, extack);
+               if (err < 0)
+                       return err;
+
+               status |= DO_SETLINK_NOTIFY;
+       }
+
+       if (linkinfo[IFLA_INFO_SLAVE_DATA]) {
+               const struct rtnl_link_ops *m_ops = NULL;
+               struct nlattr **slave_data = NULL;
+               struct net_device *master_dev;
+
+               master_dev = netdev_master_upper_dev_get(dev);
+               if (master_dev)
+                       m_ops = master_dev->rtnl_link_ops;
+
+               if (!m_ops || !m_ops->slave_changelink)
+                       return -EOPNOTSUPP;
+
+               if (m_ops->slave_maxtype > RTNL_SLAVE_MAX_TYPE)
+                       return -EINVAL;
+
+               if (m_ops->slave_maxtype) {
+                       err = nla_parse_nested_deprecated(tbs->slave_attr,
+                                                         m_ops->slave_maxtype,
+                                                         linkinfo[IFLA_INFO_SLAVE_DATA],
+                                                         m_ops->slave_policy, extack);
+                       if (err < 0)
+                               return err;
+
+                       slave_data = tbs->slave_attr;
+               }
+
+               err = m_ops->slave_changelink(master_dev, dev, tb, slave_data, extack);
+               if (err < 0)
+                       return err;
+
+               status |= DO_SETLINK_NOTIFY;
+       }
+
+       return do_setlink(skb, dev, nlmsg_data(nlh), extack, tb, status);
+}
+
 static int rtnl_group_changelink(const struct sk_buff *skb,
                struct net *net, int group,
                struct ifinfomsg *ifm,
@@ -3617,24 +3689,14 @@ out_unregister:
        goto out;
 }
 
-struct rtnl_newlink_tbs {
-       struct nlattr *tb[IFLA_MAX + 1];
-       struct nlattr *linkinfo[IFLA_INFO_MAX + 1];
-       struct nlattr *attr[RTNL_MAX_TYPE + 1];
-       struct nlattr *slave_attr[RTNL_SLAVE_MAX_TYPE + 1];
-};
-
 static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
                          struct rtnl_newlink_tbs *tbs,
                          struct netlink_ext_ack *extack)
 {
        struct nlattr ** const linkinfo = tbs->linkinfo;
        struct nlattr ** const tb = tbs->tb;
-       const struct rtnl_link_ops *m_ops;
-       struct net_device *master_dev;
        struct net *net = sock_net(skb->sk);
        const struct rtnl_link_ops *ops;
-       struct nlattr **slave_data;
        char kind[MODULE_NAME_LEN];
        struct net_device *dev;
        struct ifinfomsg *ifm;
@@ -3669,14 +3731,6 @@ replay:
                dev = NULL;
        }
 
-       master_dev = NULL;
-       m_ops = NULL;
-       if (dev) {
-               master_dev = netdev_master_upper_dev_get(dev);
-               if (master_dev)
-                       m_ops = master_dev->rtnl_link_ops;
-       }
-
        if (tb[IFLA_LINKINFO]) {
                err = nla_parse_nested_deprecated(linkinfo, IFLA_INFO_MAX,
                                                  tb[IFLA_LINKINFO],
@@ -3715,56 +3769,8 @@ replay:
                }
        }
 
-       slave_data = NULL;
-       if (m_ops) {
-               if (m_ops->slave_maxtype > RTNL_SLAVE_MAX_TYPE)
-                       return -EINVAL;
-
-               if (m_ops->slave_maxtype &&
-                   linkinfo[IFLA_INFO_SLAVE_DATA]) {
-                       err = nla_parse_nested_deprecated(tbs->slave_attr,
-                                                         m_ops->slave_maxtype,
-                                                         linkinfo[IFLA_INFO_SLAVE_DATA],
-                                                         m_ops->slave_policy,
-                                                         extack);
-                       if (err < 0)
-                               return err;
-                       slave_data = tbs->slave_attr;
-               }
-       }
-
-       if (dev) {
-               int status = 0;
-
-               if (nlh->nlmsg_flags & NLM_F_EXCL)
-                       return -EEXIST;
-               if (nlh->nlmsg_flags & NLM_F_REPLACE)
-                       return -EOPNOTSUPP;
-
-               if (linkinfo[IFLA_INFO_DATA]) {
-                       if (!ops || ops != dev->rtnl_link_ops ||
-                           !ops->changelink)
-                               return -EOPNOTSUPP;
-
-                       err = ops->changelink(dev, tb, data, extack);
-                       if (err < 0)
-                               return err;
-                       status |= DO_SETLINK_NOTIFY;
-               }
-
-               if (linkinfo[IFLA_INFO_SLAVE_DATA]) {
-                       if (!m_ops || !m_ops->slave_changelink)
-                               return -EOPNOTSUPP;
-
-                       err = m_ops->slave_changelink(master_dev, dev, tb,
-                                                     slave_data, extack);
-                       if (err < 0)
-                               return err;
-                       status |= DO_SETLINK_NOTIFY;
-               }
-
-               return do_setlink(skb, dev, ifm, extack, tb, status);
-       }
+       if (dev)
+               return rtnl_changelink(skb, nlh, ops, dev, tbs, data, extack);
 
        if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
                /* No dev found and NLM_F_CREATE not set. Requested dev does not exist,