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/pcap_kern.c b/arch/um/drivers/pcap_kern.c
index da0403e..3a750dd 100644
--- a/arch/um/drivers/pcap_kern.c
+++ b/arch/um/drivers/pcap_kern.c
@@ -31,19 +31,14 @@
printk("pcap backend, host interface %s\n", ppri->host_if);
}
-static int pcap_read(int fd, struct sk_buff **skb,
- struct uml_net_private *lp)
+static int pcap_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 pcap_user_read(fd, skb_mac_header(*skb),
- (*skb)->dev->mtu + ETH_HEADER_OTHER,
+ return pcap_user_read(fd, skb_mac_header(skb),
+ skb->dev->mtu + ETH_HEADER_OTHER,
(struct pcap_data *) &lp->user);
}
-static int pcap_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+static int pcap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
return -EPERM;
}
