[WIRELESS]: Use type safe netlink interface

Makes use of the type safe netlink interface and adds a warning
if the message is too big for NLMSG_DEFAULT_SIZE to help debug.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 16 insertions, 14 deletions

diff --git a/net/wireless/wext.c b/net/wireless/wext.c
index d6aaf65192e9..debf5191a128 100644
--- a/net/wireless/wext.c
+++ b/net/wireless/wext.c
@@ -1129,10 +1129,12 @@ static int rtnetlink_fill_iwinfo(struct sk_buff *skb, struct net_device *dev,
 {
         struct ifinfomsg *r;
         struct nlmsghdr  *nlh;
-        unsigned char    *b = skb_tail_pointer(skb);
 
-        nlh = NLMSG_PUT(skb, 0, 0, type, sizeof(*r));
-        r = NLMSG_DATA(nlh);
+        nlh = nlmsg_put(skb, 0, 0, type, sizeof(*r), 0);
+        if (nlh == NULL)
+                return -EMSGSIZE;
+
+        r = nlmsg_data(nlh);
         r->ifi_family = AF_UNSPEC;
         r->__ifi_pad = 0;
         r->ifi_type = dev->type;
@@ -1141,15 +1143,13 @@ static int rtnetlink_fill_iwinfo(struct sk_buff *skb, struct net_device *dev,
         r->ifi_change = 0;      /* Wireless changes don't affect those flags */
 
         /* Add the wireless events in the netlink packet */
-        RTA_PUT(skb, IFLA_WIRELESS, event_len, event);
+        NLA_PUT(skb, IFLA_WIRELESS, event_len, event);
 
-        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
-        return skb->len;
+        return nlmsg_end(skb, nlh);
 
-nlmsg_failure:
-rtattr_failure:
-        nlmsg_trim(skb, b);
-        return -1;
+nla_put_failure:
+        nlmsg_cancel(skb, nlh);
+        return -EMSGSIZE;
 }
 
 /* ---------------------------------------------------------------- */
@@ -1162,17 +1162,19 @@ rtattr_failure:
 static void rtmsg_iwinfo(struct net_device *dev, char *event, int event_len)
 {
         struct sk_buff *skb;
-        int size = NLMSG_GOODSIZE;
+        int err;
 
-        skb = alloc_skb(size, GFP_ATOMIC);
+        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
         if (!skb)
                 return;
 
-        if (rtnetlink_fill_iwinfo(skb, dev, RTM_NEWLINK,
-                                  event, event_len) < 0) {
+        err = rtnetlink_fill_iwinfo(skb, dev, RTM_NEWLINK, event, event_len);
+        if (err < 0) {
+                WARN_ON(err == -EMSGSIZE);
                 kfree_skb(skb);
                 return;
         }
+
         NETLINK_CB(skb).dst_group = RTNLGRP_LINK;
         skb_queue_tail(&wireless_nlevent_queue, skb);
         tasklet_schedule(&wireless_nlevent_tasklet);