ltq-ptm: Support 1508-byte MTU for RFC4638

Tested with VDSL on TP-Link WD8970, I see full 1500-byte PPP data
frames, which end up being 1526 byte Ethernet frames (including
Ethernet+VLAN headers) on the wire.

Fixes: FS#210

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This commit is contained in:
David Woodhouse 2016-10-07 15:02:13 +01:00 committed by John Crispin
parent cf458de382
commit 8a2a20e71e
2 changed files with 22 additions and 2 deletions

View file

@ -128,6 +128,7 @@ static int ptm_stop(struct net_device *);
static unsigned int ptm_poll(int, unsigned int);
static int ptm_napi_poll(struct napi_struct *, int);
static int ptm_hard_start_xmit(struct sk_buff *, struct net_device *);
static int ptm_change_mtu(struct net_device *, int);
static int ptm_ioctl(struct net_device *, struct ifreq *, int);
static void ptm_tx_timeout(struct net_device *);
@ -246,7 +247,7 @@ static struct net_device_ops g_ptm_netdev_ops = {
.ndo_start_xmit = ptm_hard_start_xmit,
.ndo_validate_addr = eth_validate_addr,
.ndo_set_mac_address = eth_mac_addr,
.ndo_change_mtu = eth_change_mtu,
.ndo_change_mtu = ptm_change_mtu,
.ndo_do_ioctl = ptm_ioctl,
.ndo_tx_timeout = ptm_tx_timeout,
};
@ -451,6 +452,15 @@ PTM_HARD_START_XMIT_FAIL:
return NETDEV_TX_OK;
}
static int ptm_change_mtu(struct net_device *dev, int mtu)
{
/* Allow up to 1508 bytes, for RFC4638 */
if (mtu < 68 || mtu > ETH_DATA_LEN + 8)
return -EINVAL;
dev->mtu = mtu;
return 0;
}
static int ptm_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
int ndev;

View file

@ -74,6 +74,7 @@ static int ptm_stop(struct net_device *);
static unsigned int ptm_poll(int, unsigned int);
static int ptm_napi_poll(struct napi_struct *, int);
static int ptm_hard_start_xmit(struct sk_buff *, struct net_device *);
static int ptm_change_mtu(struct net_device *, int);
static int ptm_ioctl(struct net_device *, struct ifreq *, int);
static void ptm_tx_timeout(struct net_device *);
@ -114,7 +115,7 @@ static struct net_device_ops g_ptm_netdev_ops = {
.ndo_start_xmit = ptm_hard_start_xmit,
.ndo_validate_addr = eth_validate_addr,
.ndo_set_mac_address = eth_mac_addr,
.ndo_change_mtu = eth_change_mtu,
.ndo_change_mtu = ptm_change_mtu,
.ndo_do_ioctl = ptm_ioctl,
.ndo_tx_timeout = ptm_tx_timeout,
};
@ -358,6 +359,15 @@ PTM_HARD_START_XMIT_FAIL:
return 0;
}
static int ptm_change_mtu(struct net_device *dev, int mtu)
{
/* Allow up to 1508 bytes, for RFC4638 */
if (mtu < 68 || mtu > ETH_DATA_LEN + 8)
return -EINVAL;
dev->mtu = mtu;
return 0;
}
static int ptm_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
ASSERT(dev == g_net_dev[0], "incorrect device");