2007-07-22 11:06:35

by Thomas Graf

[permalink] [raw]
Subject: [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 <[email protected]>

Index: net-2.6/net/wireless/wext.c
===================================================================
--- net-2.6.orig/net/wireless/wext.c 2007-07-22 11:41:46.000000000 +0200
+++ net-2.6/net/wireless/wext.c 2007-07-22 12:00:17.000000000 +0200
@@ -1129,10 +1129,12 @@ static int rtnetlink_fill_iwinfo(struct
{
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
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);