Re: MC 7304 ipv4v6

[Bjørn Mork <bjorn mork no>]

Bjørn Mork <bjorn mork no> writes:
> Dan Williams <dcbw redhat com> writes:
> > On Tue, 2015-11-24 at 22:51 +0100, Bjørn Mork wrote:
> >
> > My vote would be sysfs, with values "raw-ip" or "802.3" that you can
> > read and write to the file.  At least then they are human-readable. 
> >  It's also easier to use from scripts than parsing ethtool output.
>
> Maybe even easier with a boolean qmi/raw_ip file, since we are only going
> to offer two alternatives anyway?  Then you don't have to figure out
> what strings are accepted, and we won't end up having to parse
> 'raw-ip/rawip/raw_ip/rwa-ip/rawIP/etc'.

Including a demo patch (not tested...) to illustrate what I mean:

 $ cat /sys/class/net/wwan1/qmi/raw_ip 
 N
 # echo Y >/sys/class/net/wwan1/qmi/raw_ip

etc

> From 97df402dab83feb14a7cb61fb7fa950e0bcf8c1d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn mork no>
Date: Mon, 15 Apr 2013 21:55:34 +0200
Subject: [PATCH] net: qmi_wwan: add raw IP support with fake ethernet headers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Bjørn Mork <bjorn mork no>
---
 drivers/net/usb/qmi_wwan.c | 66 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 65 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index af1267fb1139..428b46453efc 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -48,11 +48,55 @@
 struct qmi_wwan_state {
        struct usb_driver *subdriver;
        atomic_t pmcount;
-       unsigned long unused;
+       unsigned long flags;
        struct usb_interface *control;
        struct usb_interface *data;
 };
 
+enum qmi_wwan_flags {
+       QMI_WWAN_FLAG_RAWIP = 1 << 0,
+};
+
+static ssize_t raw_ip_show(struct device *d, struct device_attribute *attr, char *buf)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct qmi_wwan_state *info = (void *)&dev->data;
+
+       return sprintf(buf, "%c\n", info->flags & QMI_WWAN_FLAG_RAWIP ? 'Y' : 'N');
+}
+
+static ssize_t raw_ip_store(struct device *d,  struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct usbnet *dev = netdev_priv(to_net_dev(d));
+       struct qmi_wwan_state *info = (void *)&dev->data;
+       bool enable;
+
+       if (strtobool(buf, &enable))
+               return -EINVAL;
+
+       if (enable) {
+               info->flags |= QMI_WWAN_FLAG_RAWIP;
+               /* cannot do arp in raw IP mode, but must do in 802.3 mode */
+               dev->net->flags |= IFF_NOARP;
+       } else {
+               info->flags &= ~QMI_WWAN_FLAG_RAWIP;
+               dev->net->flags &= ~IFF_NOARP;
+       }
+       return len;
+}
+
+static DEVICE_ATTR_RW(raw_ip);
+
+static struct attribute *qmi_wwan_sysfs_attrs[] = {
+       &dev_attr_raw_ip.attr,
+       NULL,
+};
+
+static struct attribute_group qmi_wwan_sysfs_attr_group = {
+       .name = "qmi",
+       .attrs = qmi_wwan_sysfs_attrs,
+};
+
 /* default ethernet address used by the modem */
 static const u8 default_modem_addr[ETH_ALEN] = {0x02, 0x50, 0xf3};
 
@@ -114,6 +158,24 @@ fix_dest:
        return 1;
 }
 
+static struct sk_buff *qmi_wwan_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
+{
+       struct qmi_wwan_state *info = (void *)&dev->data;
+
+       if ((skb->len <= ETH_HLEN) || !(info->flags & QMI_WWAN_FLAG_RAWIP))
+               goto out;
+
+       /* only pull header if datagram is IPv4 or IPv6 */
+       skb_reset_mac_header(skb);
+       switch (eth_hdr(skb)->h_proto) {
+       case htons(ETH_P_IP):
+       case htons(ETH_P_IPV6):
+               skb_pull(skb, ETH_HLEN);
+       }
+out:
+       return skb;
+}
+
 /* very simplistic detection of IPv4 or IPv6 headers */
 static bool possibly_iphdr(const char *data)
 {
@@ -312,6 +374,7 @@ static int qmi_wwan_bind(struct usbnet *dev, struct usb_interface *intf)
                dev->net->dev_addr[0] &= 0xbf;  /* clear "IP" bit */
        }
        dev->net->netdev_ops = &qmi_wwan_netdev_ops;
+       dev->net->sysfs_groups[0] = &qmi_wwan_sysfs_attr_group;
 err:
        return status;
 }
@@ -397,6 +460,7 @@ static const struct driver_info     qmi_wwan_info = {
        .unbind         = qmi_wwan_unbind,
        .manage_power   = qmi_wwan_manage_power,
        .rx_fixup       = qmi_wwan_rx_fixup,
+       .tx_fixup       = qmi_wwan_tx_fixup,
 };
 
 #define HUAWEI_VENDOR_ID       0x12D1
-- 
2.1.4