From b53f35a8093e6aed7e8e880eaa0b89a3d2fdfb0a Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Tue, 16 Oct 2007 01:27:31 -0700 Subject: 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/drivers/net_kern.c | 42 ++++++++---------------------------------- 1 file changed, 8 insertions(+), 34 deletions(-) (limited to 'arch/um/drivers/net_kern.c') diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c index b097a24c1496..59811cc880e0 100644 --- a/arch/um/drivers/net_kern.c +++ b/arch/um/drivers/net_kern.c @@ -41,16 +41,16 @@ static int uml_net_rx(struct net_device *dev) 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 @@ static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev) 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_set_mac(struct net_device *dev, void *addr) 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 @@ static void eth_configure(int n, void *init, char *mac, .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 @@ static void eth_configure(int n, void *init, char *mac, .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 @@ static void eth_configure(int n, void *init, char *mac, 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 @@ static void close_devices(void) __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) -- cgit v1.2.3-59-g8ed1b