nl80211: fix dump callbacks

Julius Volz pointed out that the dump callbacks in nl80211 were
broken and fixed one of them. This patch fixes the other three
and also addresses the TODOs there.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Julius Volz <juliusv@google.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/wireless/nl80211.c

@@ -29,16 +29,16 @@ static struct genl_family nl80211_fam = {
 };
 
 /* internal helper: get drv and dev */
-static int get_drv_dev_by_info_ifindex(struct genl_info *info,
+static int get_drv_dev_by_info_ifindex(struct nlattr **attrs,
 				       struct cfg80211_registered_device **drv,
 				       struct net_device **dev)
 {
 	int ifindex;
 
-	if (!info->attrs[NL80211_ATTR_IFINDEX])
+	if (!attrs[NL80211_ATTR_IFINDEX])
 		return -EINVAL;
 
-	ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
+	ifindex = nla_get_u32(attrs[NL80211_ATTR_IFINDEX]);
 	*dev = dev_get_by_index(&init_net, ifindex);
 	if (!*dev)
 		return -ENODEV;
@@ -291,21 +291,31 @@ static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *
 
 	mutex_lock(&cfg80211_drv_mutex);
 	list_for_each_entry(dev, &cfg80211_drv_list, list) {
-		if (++wp_idx < wp_start)
+		if (wp_idx < wp_start) {
+			wp_idx++;
 			continue;
+		}
 		if_idx = 0;
 
 		mutex_lock(&dev->devlist_mtx);
 		list_for_each_entry(wdev, &dev->netdev_list, list) {
-			if (++if_idx < if_start)
+			if (if_idx < if_start) {
+				if_idx++;
 				continue;
+			}
 			if (nl80211_send_iface(skb, NETLINK_CB(cb->skb).pid,
 					       cb->nlh->nlmsg_seq, NLM_F_MULTI,
-					       wdev->netdev) < 0)
-				break;
+					       wdev->netdev) < 0) {
+				mutex_unlock(&dev->devlist_mtx);
+				goto out;
+			}
+			if_idx++;
 		}
 		mutex_unlock(&dev->devlist_mtx);
+
+		wp_idx++;
 	}
+ out:
 	mutex_unlock(&cfg80211_drv_mutex);
 
 	cb->args[0] = wp_idx;
@@ -321,7 +331,7 @@ static int nl80211_get_interface(struct sk_buff *skb, struct genl_info *info)
 	struct net_device *netdev;
 	int err;
 
-	err = get_drv_dev_by_info_ifindex(info, &dev, &netdev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &dev, &netdev);
 	if (err)
 		return err;
 
@@ -392,7 +402,7 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
 	} else
 		return -EINVAL;
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 	ifindex = dev->ifindex;
@@ -477,7 +487,7 @@ static int nl80211_del_interface(struct sk_buff *skb, struct genl_info *info)
 	int ifindex, err;
 	struct net_device *dev;
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 	ifindex = dev->ifindex;
@@ -545,7 +555,7 @@ static int nl80211_get_key(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NL80211_ATTR_MAC])
 		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -618,7 +628,7 @@ static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)
 	if (!info->attrs[NL80211_ATTR_KEY_DEFAULT])
 		return -EINVAL;
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -699,7 +709,7 @@ static int nl80211_new_key(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -735,7 +745,7 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NL80211_ATTR_MAC])
 		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -764,7 +774,7 @@ static int nl80211_addset_beacon(struct sk_buff *skb, struct genl_info *info)
 	struct beacon_parameters params;
 	int haveinfo = 0;
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -843,7 +853,7 @@ static int nl80211_del_beacon(struct sk_buff *skb, struct genl_info *info)
 	int err;
 	struct net_device *dev;
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -937,67 +947,78 @@ static int nl80211_send_station(struct sk_buff *msg, u32 pid, u32 seq,
 }
 
 static int nl80211_dump_station(struct sk_buff *skb,
-		struct netlink_callback *cb)
+				struct netlink_callback *cb)
 {
-	int wp_idx = 0;
-	int if_idx = 0;
-	int sta_idx = cb->args[2];
-	int wp_start = cb->args[0];
-	int if_start = cb->args[1];
 	struct station_info sinfo;
 	struct cfg80211_registered_device *dev;
-	struct wireless_dev *wdev;
+	struct net_device *netdev;
 	u8 mac_addr[ETH_ALEN];
+	int ifidx = cb->args[0];
+	int sta_idx = cb->args[1];
 	int err;
-	int exit = 0;
 
-	/* TODO: filter by device */
-	mutex_lock(&cfg80211_drv_mutex);
-	list_for_each_entry(dev, &cfg80211_drv_list, list) {
-		if (exit)
+	if (!ifidx) {
+		err = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
+				  nl80211_fam.attrbuf, nl80211_fam.maxattr,
+				  nl80211_policy);
+		if (err)
+			return err;
+
+		if (!nl80211_fam.attrbuf[NL80211_ATTR_IFINDEX])
+			return -EINVAL;
+
+		ifidx = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_IFINDEX]);
+		if (!ifidx)
+			return -EINVAL;
+	}
+
+	netdev = dev_get_by_index(&init_net, ifidx);
+	if (!netdev)
+		return -ENODEV;
+
+	dev = cfg80211_get_dev_from_ifindex(ifidx);
+	if (IS_ERR(dev)) {
+		err = PTR_ERR(dev);
+		goto out_put_netdev;
+	}
+
+	if (!dev->ops->dump_station) {
+		err = -ENOSYS;
+		goto out_err;
+	}
+
+	rtnl_lock();
+
+	while (1) {
+		err = dev->ops->dump_station(&dev->wiphy, netdev, sta_idx,
+					     mac_addr, &sinfo);
+		if (err == -ENOENT)
 			break;
-		if (++wp_idx < wp_start)
-			continue;
-		if_idx = 0;
+		if (err)
+			goto out_err_rtnl;
 
-		mutex_lock(&dev->devlist_mtx);
-		list_for_each_entry(wdev, &dev->netdev_list, list) {
-			if (exit)
-				break;
-			if (++if_idx < if_start)
-				continue;
-			if (!dev->ops->dump_station)
-				continue;
+		if (nl80211_send_station(skb,
+				NETLINK_CB(cb->skb).pid,
+				cb->nlh->nlmsg_seq, NLM_F_MULTI,
+				netdev, mac_addr,
+				&sinfo) < 0)
+			goto out;
 
-			for (;; ++sta_idx) {
-				rtnl_lock();
-				err = dev->ops->dump_station(&dev->wiphy,
-						wdev->netdev, sta_idx, mac_addr,
-						&sinfo);
-				rtnl_unlock();
-				if (err) {
-					sta_idx = 0;
-					break;
-				}
-				if (nl80211_send_station(skb,
-						NETLINK_CB(cb->skb).pid,
-						cb->nlh->nlmsg_seq, NLM_F_MULTI,
-						wdev->netdev, mac_addr,
-						&sinfo) < 0) {
-					exit = 1;
-					break;
-				}
-			}
-		}
-		mutex_unlock(&dev->devlist_mtx);
+		sta_idx++;
 	}
-	mutex_unlock(&cfg80211_drv_mutex);
 
-	cb->args[0] = wp_idx;
-	cb->args[1] = if_idx;
-	cb->args[2] = sta_idx;
 
-	return skb->len;
+ out:
+	cb->args[1] = sta_idx;
+	err = skb->len;
+ out_err_rtnl:
+	rtnl_unlock();
+ out_err:
+	cfg80211_put_dev(dev);
+ out_put_netdev:
+	dev_put(netdev);
+
+	return err;
 }
 
 static int nl80211_get_station(struct sk_buff *skb, struct genl_info *info)
@@ -1016,7 +1037,7 @@ static int nl80211_get_station(struct sk_buff *skb, struct genl_info *info)
 
 	mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -1112,7 +1133,7 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
 		params.plink_action =
 		    nla_get_u8(info->attrs[NL80211_ATTR_STA_PLINK_ACTION]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -1172,7 +1193,7 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
 				&params.station_flags))
 		return -EINVAL;
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -1207,7 +1228,7 @@ static int nl80211_del_station(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NL80211_ATTR_MAC])
 		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -1277,68 +1298,78 @@ static int nl80211_send_mpath(struct sk_buff *msg, u32 pid, u32 seq,
 }
 
 static int nl80211_dump_mpath(struct sk_buff *skb,
-		struct netlink_callback *cb)
+			      struct netlink_callback *cb)
 {
-	int wp_idx = 0;
-	int if_idx = 0;
-	int sta_idx = cb->args[2];
-	int wp_start = cb->args[0];
-	int if_start = cb->args[1];
 	struct mpath_info pinfo;
 	struct cfg80211_registered_device *dev;
-	struct wireless_dev *wdev;
+	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;
-	int exit = 0;
 
-	/* TODO: filter by device */
-	mutex_lock(&cfg80211_drv_mutex);
-	list_for_each_entry(dev, &cfg80211_drv_list, list) {
-		if (exit)
+	if (!ifidx) {
+		err = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
+				  nl80211_fam.attrbuf, nl80211_fam.maxattr,
+				  nl80211_policy);
+		if (err)
+			return err;
+
+		if (!nl80211_fam.attrbuf[NL80211_ATTR_IFINDEX])
+			return -EINVAL;
+
+		ifidx = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_IFINDEX]);
+		if (!ifidx)
+			return -EINVAL;
+	}
+
+	netdev = dev_get_by_index(&init_net, ifidx);
+	if (!netdev)
+		return -ENODEV;
+
+	dev = cfg80211_get_dev_from_ifindex(ifidx);
+	if (IS_ERR(dev)) {
+		err = PTR_ERR(dev);
+		goto out_put_netdev;
+	}
+
+	if (!dev->ops->dump_mpath) {
+		err = -ENOSYS;
+		goto out_err;
+	}
+
+	rtnl_lock();
+
+	while (1) {
+		err = dev->ops->dump_mpath(&dev->wiphy, netdev, path_idx,
+					   dst, next_hop, &pinfo);
+		if (err == -ENOENT)
 			break;
-		if (++wp_idx < wp_start)
-			continue;
-		if_idx = 0;
+		if (err)
+			goto out_err_rtnl;
 
-		mutex_lock(&dev->devlist_mtx);
-		list_for_each_entry(wdev, &dev->netdev_list, list) {
-			if (exit)
-				break;
-			if (++if_idx < if_start)
-				continue;
-			if (!dev->ops->dump_mpath)
-				continue;
+		if (nl80211_send_mpath(skb, NETLINK_CB(cb->skb).pid,
+				       cb->nlh->nlmsg_seq, NLM_F_MULTI,
+				       netdev, dst, next_hop,
+				       &pinfo) < 0)
+			goto out;
 
-			for (;; ++sta_idx) {
-				rtnl_lock();
-				err = dev->ops->dump_mpath(&dev->wiphy,
-						wdev->netdev, sta_idx, dst,
-						next_hop, &pinfo);
-				rtnl_unlock();
-				if (err) {
-					sta_idx = 0;
-					break;
-				}
-				if (nl80211_send_mpath(skb,
-						NETLINK_CB(cb->skb).pid,
-						cb->nlh->nlmsg_seq, NLM_F_MULTI,
-						wdev->netdev, dst, next_hop,
-						&pinfo) < 0) {
-					exit = 1;
-					break;
-				}
-			}
-		}
-		mutex_unlock(&dev->devlist_mtx);
+		path_idx++;
 	}
-	mutex_unlock(&cfg80211_drv_mutex);
 
-	cb->args[0] = wp_idx;
-	cb->args[1] = if_idx;
-	cb->args[2] = sta_idx;
 
-	return skb->len;
+ out:
+	cb->args[1] = path_idx;
+	err = skb->len;
+ out_err_rtnl:
+	rtnl_unlock();
+ out_err:
+	cfg80211_put_dev(dev);
+ out_put_netdev:
+	dev_put(netdev);
+
+	return err;
 }
 
 static int nl80211_get_mpath(struct sk_buff *skb, struct genl_info *info)
@@ -1358,7 +1389,7 @@ static int nl80211_get_mpath(struct sk_buff *skb, struct genl_info *info)
 
 	dst = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -1411,7 +1442,7 @@ static int nl80211_set_mpath(struct sk_buff *skb, struct genl_info *info)
 	dst = nla_data(info->attrs[NL80211_ATTR_MAC]);
 	next_hop = nla_data(info->attrs[NL80211_ATTR_MPATH_NEXT_HOP]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -1446,7 +1477,7 @@ static int nl80211_new_mpath(struct sk_buff *skb, struct genl_info *info)
 	dst = nla_data(info->attrs[NL80211_ATTR_MAC]);
 	next_hop = nla_data(info->attrs[NL80211_ATTR_MPATH_NEXT_HOP]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;
 
@@ -1475,7 +1506,7 @@ static int nl80211_del_mpath(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NL80211_ATTR_MAC])
 		dst = nla_data(info->attrs[NL80211_ATTR_MAC]);
 
-	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
+	err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
 	if (err)
 		return err;