uml: network driver MTU cleanups
A bunch of MTU-related cleanups in the network code.
First, there is the addition of the notion of a maximally-sized packet, which
is the MTU plus headers. This is used to size the skb that will receive a
packet. This allows ether_adjust_skb to go away, as it was used to resize the
skb after it was allocated.
Since the skb passed into the low-level read routine is no longer resized, and
possibly reallocated, there, they (and the write routines) don't need to get
an sk_buff **. They just need the sk_buff * now. The callers of
ether_adjust_skb still need to do the skb_put, so that's now inlined.
The MAX_PACKET definitions in most of the drivers are gone.
The set_mtu methods were all the same and did nothing, so they can be
removed.
The ethertap driver had a typo which doubled the size of the packet rather
than adding two bytes to it. It also wasn't defining its setup_size, causing
a zero-byte kmalloc and crash when the invalid pointer returned from kmalloc
was dereferenced.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/drivers/mcast_kern.c b/arch/um/drivers/mcast_kern.c
index 5027b87..822092f 100644
--- a/arch/um/drivers/mcast_kern.c
+++ b/arch/um/drivers/mcast_kern.c
@@ -39,18 +39,15 @@
dpri->addr, dpri->port, dpri->ttl);
}
-static int mcast_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+static int mcast_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
- *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
- if (*skb == NULL)
- return -ENOMEM;
- return net_recvfrom(fd, skb_mac_header(*skb),
- (*skb)->dev->mtu + ETH_HEADER_OTHER);
+ return net_recvfrom(fd, skb_mac_header(skb),
+ skb->dev->mtu + ETH_HEADER_OTHER);
}
-static int mcast_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+static int mcast_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
- return mcast_user_write(fd, (*skb)->data, (*skb)->len,
+ return mcast_user_write(fd, skb->data, skb->len,
(struct mcast_data *) &lp->user);
}