nl80211: reduce dumping boilerplate

Consolidate boilerplate code needed for .dumpit
calls operating on netdevs.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 59 insertions, 92 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index ca8d04cb172f..0c9497170f1f 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -198,6 +198,47 @@ static int nl80211_get_ifidx(struct netlink_callback *cb)
         return res;
 }
 
+static int nl80211_prepare_netdev_dump(struct sk_buff *skb,
+                                       struct netlink_callback *cb,
+                                       struct cfg80211_registered_device **rdev,
+                                       struct net_device **dev)
+{
+        int ifidx = cb->args[0];
+        int err;
+
+        if (!ifidx)
+                ifidx = nl80211_get_ifidx(cb);
+        if (ifidx < 0)
+                return ifidx;
+
+        cb->args[0] = ifidx;
+
+        rtnl_lock();
+
+        *dev = __dev_get_by_index(sock_net(skb->sk), ifidx);
+        if (!*dev) {
+                err = -ENODEV;
+                goto out_rtnl;
+        }
+
+        *rdev = cfg80211_get_dev_from_ifindex(sock_net(skb->sk), ifidx);
+        if (IS_ERR(dev)) {
+                err = PTR_ERR(dev);
+                goto out_rtnl;
+        }
+
+        return 0;
+ out_rtnl:
+        rtnl_unlock();
+        return err;
+}
+
+static void nl80211_finish_netdev_dump(struct cfg80211_registered_device *rdev)
+{
+        cfg80211_unlock_rdev(rdev);
+        rtnl_unlock();
+}
+
 /* IE validation */
 static bool is_valid_ie_attr(const struct nlattr *attr)
 {
@@ -1796,28 +1837,12 @@ static int nl80211_dump_station(struct sk_buff *skb,
         struct cfg80211_registered_device *dev;
         struct net_device *netdev;
         u8 mac_addr[ETH_ALEN];
-        int ifidx = cb->args[0];
         int sta_idx = cb->args[1];
         int err;
 
-        if (!ifidx)
-                ifidx = nl80211_get_ifidx(cb);
-        if (ifidx < 0)
-                return ifidx;
-
-        rtnl_lock();
-
-        netdev = __dev_get_by_index(sock_net(skb->sk), ifidx);
-        if (!netdev) {
-                err = -ENODEV;
-                goto out_rtnl;
-        }
-
-        dev = cfg80211_get_dev_from_ifindex(sock_net(skb->sk), ifidx);
-        if (IS_ERR(dev)) {
-                err = PTR_ERR(dev);
-                goto out_rtnl;
-        }
+        err = nl80211_prepare_netdev_dump(skb, cb, &dev, &netdev);
+        if (err)
+                return err;
 
         if (!dev->ops->dump_station) {
                 err = -EOPNOTSUPP;
@@ -1847,9 +1872,7 @@ static int nl80211_dump_station(struct sk_buff *skb,
         cb->args[1] = sta_idx;
         err = skb->len;
  out_err:
-        cfg80211_unlock_rdev(dev);
- out_rtnl:
-        rtnl_unlock();
+        nl80211_finish_netdev_dump(dev);
 
         return err;
 }
@@ -2169,28 +2192,12 @@ static int nl80211_dump_mpath(struct sk_buff *skb,
         struct net_device *netdev;
         u8 dst[ETH_ALEN];
         u8 next_hop[ETH_ALEN];
-        int ifidx = cb->args[0];
         int path_idx = cb->args[1];
         int err;
 
-        if (!ifidx)
-                ifidx = nl80211_get_ifidx(cb);
-        if (ifidx < 0)
-                return ifidx;
-
-        rtnl_lock();
-
-        netdev = __dev_get_by_index(sock_net(skb->sk), ifidx);
-        if (!netdev) {
-                err = -ENODEV;
-                goto out_rtnl;
-        }
-
-        dev = cfg80211_get_dev_from_ifindex(sock_net(skb->sk), ifidx);
-        if (IS_ERR(dev)) {
-                err = PTR_ERR(dev);
-                goto out_rtnl;
-        }
+        err = nl80211_prepare_netdev_dump(skb, cb, &dev, &netdev);
+        if (err)
+                return err;
 
         if (!dev->ops->dump_mpath) {
                 err = -EOPNOTSUPP;
@@ -2224,10 +2231,7 @@ static int nl80211_dump_mpath(struct sk_buff *skb,
         cb->args[1] = path_idx;
         err = skb->len;
  out_err:
-        cfg80211_unlock_rdev(dev);
- out_rtnl:
-        rtnl_unlock();
-
+        nl80211_finish_netdev_dump(dev);
         return err;
 }
 
@@ -3034,25 +3038,12 @@ static int nl80211_dump_scan(struct sk_buff *skb,
         struct net_device *dev;
         struct cfg80211_internal_bss *scan;
         struct wireless_dev *wdev;
-        int ifidx = cb->args[0];
         int start = cb->args[1], idx = 0;
         int err;
 
-        if (!ifidx)
-                ifidx = nl80211_get_ifidx(cb);
-        if (ifidx < 0)
-                return ifidx;
-        cb->args[0] = ifidx;
-
-        dev = dev_get_by_index(sock_net(skb->sk), ifidx);
-        if (!dev)
-                return -ENODEV;
-
-        rdev = cfg80211_get_dev_from_ifindex(sock_net(skb->sk), ifidx);
-        if (IS_ERR(rdev)) {
-                err = PTR_ERR(rdev);
-                goto out_put_netdev;
-        }
+        err = nl80211_prepare_netdev_dump(skb, cb, &rdev, &dev);
+        if (err)
+                return err;
 
         wdev = dev->ieee80211_ptr;
 
@@ -3068,21 +3059,17 @@ static int nl80211_dump_scan(struct sk_buff *skb,
                                 cb->nlh->nlmsg_seq, NLM_F_MULTI,
                                 rdev, wdev, scan) < 0) {
                         idx--;
-                        goto out;
+                        break;
                 }
         }
 
- out:
         spin_unlock_bh(&rdev->bss_lock);
         wdev_unlock(wdev);
 
         cb->args[1] = idx;
-        err = skb->len;
-        cfg80211_unlock_rdev(rdev);
- out_put_netdev:
-        dev_put(dev);
+        nl80211_finish_netdev_dump(rdev);
 
-        return err;
+        return skb->len;
 }
 
 static int nl80211_send_survey(struct sk_buff *msg, u32 pid, u32 seq,
@@ -3130,29 +3117,12 @@ static int nl80211_dump_survey(struct sk_buff *skb,
         struct survey_info survey;
         struct cfg80211_registered_device *dev;
         struct net_device *netdev;
-        int ifidx = cb->args[0];
         int survey_idx = cb->args[1];
         int res;
 
-        if (!ifidx)
-                ifidx = nl80211_get_ifidx(cb);
-        if (ifidx < 0)
-                return ifidx;
-        cb->args[0] = ifidx;
-
-        rtnl_lock();
-
-        netdev = __dev_get_by_index(sock_net(skb->sk), ifidx);
-        if (!netdev) {
-                res = -ENODEV;
-                goto out_rtnl;
-        }
-
-        dev = cfg80211_get_dev_from_ifindex(sock_net(skb->sk), ifidx);
-        if (IS_ERR(dev)) {
-                res = PTR_ERR(dev);
-                goto out_rtnl;
-        }
+        res = nl80211_prepare_netdev_dump(skb, cb, &dev, &netdev);
+        if (res)
+                return res;
 
         if (!dev->ops->dump_survey) {
                 res = -EOPNOTSUPP;
@@ -3180,10 +3150,7 @@ static int nl80211_dump_survey(struct sk_buff *skb,
         cb->args[1] = survey_idx;
         res = skb->len;
  out_err:
-        cfg80211_unlock_rdev(dev);
- out_rtnl:
-        rtnl_unlock();
-
+        nl80211_finish_netdev_dump(dev);
         return res;
 }