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/net_kern.c b/arch/um/drivers/net_kern.c
index b097a24..59811cc 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -41,16 +41,16 @@
struct sk_buff *skb;
/* If we can't allocate memory, try again next round. */
- skb = dev_alloc_skb(dev->mtu);
+ skb = dev_alloc_skb(lp->max_packet);
if (skb == NULL) {
lp->stats.rx_dropped++;
return 0;
}
skb->dev = dev;
- skb_put(skb, dev->mtu);
+ skb_put(skb, lp->max_packet);
skb_reset_mac_header(skb);
- pkt_len = (*lp->read)(lp->fd, &skb, lp);
+ pkt_len = (*lp->read)(lp->fd, skb, lp);
if (pkt_len > 0) {
skb_trim(skb, pkt_len);
@@ -178,7 +178,7 @@
spin_lock_irqsave(&lp->lock, flags);
- len = (*lp->write)(lp->fd, &skb, lp);
+ len = (*lp->write)(lp->fd, skb, lp);
if (len == skb->len) {
lp->stats.tx_packets++;
@@ -240,22 +240,9 @@
static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
{
- struct uml_net_private *lp = dev->priv;
- int err = 0;
-
- spin_lock_irq(&lp->lock);
-
- new_mtu = (*lp->set_mtu)(new_mtu, &lp->user);
- if (new_mtu < 0) {
- err = new_mtu;
- goto out;
- }
-
dev->mtu = new_mtu;
- out:
- spin_unlock_irq(&lp->lock);
- return err;
+ return 0;
}
static void uml_net_get_drvinfo(struct net_device *dev,
@@ -427,6 +414,7 @@
.dev = dev,
.fd = -1,
.mac = { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
+ .max_packet = transport->user->max_packet,
.protocol = transport->kern->protocol,
.open = transport->user->open,
.close = transport->user->close,
@@ -434,8 +422,7 @@
.read = transport->kern->read,
.write = transport->kern->write,
.add_address = transport->user->add_address,
- .delete_address = transport->user->delete_address,
- .set_mtu = transport->user->set_mtu });
+ .delete_address = transport->user->delete_address });
init_timer(&lp->tl);
spin_lock_init(&lp->lock);
@@ -447,7 +434,7 @@
goto out_unregister;
set_ether_mac(dev, device->mac);
- dev->mtu = transport->user->max_packet;
+ dev->mtu = transport->user->mtu;
dev->open = uml_net_open;
dev->hard_start_xmit = uml_net_start_xmit;
dev->stop = uml_net_close;
@@ -807,19 +794,6 @@
__uml_exitcall(close_devices);
-struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra)
-{
- if ((skb != NULL) && (skb_tailroom(skb) < extra)) {
- struct sk_buff *skb2;
-
- skb2 = skb_copy_expand(skb, 0, extra, GFP_ATOMIC);
- dev_kfree_skb(skb);
- skb = skb2;
- }
- if (skb != NULL) skb_put(skb, extra);
- return skb;
-}
-
void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
void *),
void *arg)