From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756623Ab1KIT3M (ORCPT ); Wed, 9 Nov 2011 14:29:12 -0500 Received: from nox.prolixium.com ([64.16.214.60]:37961 "EHLO nox.prolixium.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751217Ab1KIT3L (ORCPT ); Wed, 9 Nov 2011 14:29:11 -0500 X-Greylist: delayed 1912 seconds by postgrey-1.27 at vger.kernel.org; Wed, 09 Nov 2011 14:29:11 EST Date: Wed, 9 Nov 2011 13:57:14 -0500 From: Mark Kamichoff To: Dan Williams Cc: oliver@neukum.name, gregkh@suse.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net/usb: Misc. fixes for the LG-VL600 LTE USB modem Message-ID: <20111109185714.GA15884@prolixium.com> References: <1320808200-28209-1-git-send-email-prox@prolixium.com> <1320861104.24903.4.camel@dcbw.foobar.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1320861104.24903.4.camel@dcbw.foobar.com> X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: prox@prolixium.com X-SA-Exim-Scanned: No (on nox.prolixium.com); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 09, 2011 at 11:51:44AM -0600, Dan Williams wrote: > On Tue, 2011-11-08 at 22:10 -0500, Mark Kamichoff wrote: > > Add checking for valid magic values (needed for stability in the event > > corrupted packets are received) and remove some other unneeded checks. > > Also, fix flagging device as WWAN (Bugzilla bug #39952). > > > > Signed-off-by: Mark Kamichoff > > --- > > drivers/net/usb/cdc_ether.c | 2 +- > > drivers/net/usb/lg-vl600.c | 30 ++++++++++++++---------------- > > 2 files changed, 15 insertions(+), 17 deletions(-) > > > > diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c > > index c924ea2..99ed6eb 100644 > > --- a/drivers/net/usb/cdc_ether.c > > +++ b/drivers/net/usb/cdc_ether.c > > @@ -567,7 +567,7 @@ static const struct usb_device_id products [] = { > > { > > USB_DEVICE_AND_INTERFACE_INFO(0x1004, 0x61aa, USB_CLASS_COMM, > > USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE), > > - .driver_info = (unsigned long)&wwan_info, > > + .driver_info = 0, > > }, > > > > /* > > diff --git a/drivers/net/usb/lg-vl600.c b/drivers/net/usb/lg-vl600.c > > index d43db32..b975a39 100644 > > --- a/drivers/net/usb/lg-vl600.c > > +++ b/drivers/net/usb/lg-vl600.c > > @@ -144,10 +144,11 @@ static int vl600_rx_fixup(struct usbnet *dev, struct sk_buff *skb) > > } > > > > frame = (struct vl600_frame_hdr *) buf->data; > > - /* NOTE: Should check that frame->magic == 0x53544448? > > - * Otherwise if we receive garbage at the beginning of the frame > > - * we may end up allocating a huge buffer and saving all the > > - * future incoming data into it. */ > > + /* Yes, check that frame->magic == 0x53544448 (or 0x44544d48), > > + * otherwise we may run out of memory w/a bad packet */ > > + if (ntohl(frame->magic) != 0x53544448 && > > + ntohl(frame->magic) != 0x44544d48) > > + goto error; > > > > if (buf->len < sizeof(*frame) || > > buf->len != le32_to_cpup(&frame->len)) { > > @@ -209,8 +210,9 @@ static int vl600_rx_fixup(struct usbnet *dev, struct sk_buff *skb) > > * for IPv6 packets, and set the ethertype to IPv6 > > * (0x86dd) so Linux can understand it. > > */ > > - if ((buf->data[sizeof(*ethhdr)] & 0xf0) == 0x60) > > - ethhdr->h_proto = __constant_htons(ETH_P_IPV6); > > + if ((buf->data[sizeof(*ethhdr)] & 0xf0) == 0x60) { > > + ethhdr->h_proto = htons(ETH_P_IPV6); > > + } > > This change seems somewhat gratuitous; what's the reason for (a) the > switch from __constant_htons() to plain htons() and (b) adding the {} ? > > Dan For (a), it's my understanding that __constant_htons() should be used only for initializers and htons() used in other cases, since it handles checking for constants. I suppose you're right and this is a little gratuitous, but I wanted to keep things clean. As far as (b), sorry! That's an error on my part. I must have been practicing another coding style at the time. The braces certainly shouldn't be there, let me know if I should resubmit. - Mark > > > } > > > > if (count) { > > @@ -296,6 +298,11 @@ encapsulate: > > * overwrite the remaining fields. > > */ > > packet = (struct vl600_pkt_hdr *) skb->data; > > + /* The VL600 wants IPv6 packets to have an IPv4 ethertype > > + * Since this modem only supports IPv4 and IPv6, just set all > > + * frames to 0x0800 (ETH_P_IP) > > + */ > > + packet->h_proto = htons(ETH_P_IP); > > memset(&packet->dummy, 0, sizeof(packet->dummy)); > > packet->len = cpu_to_le32(orig_len); > > > > @@ -308,21 +315,12 @@ encapsulate: > > if (skb->len < full_len) /* Pad */ > > skb_put(skb, full_len - skb->len); > > > > - /* The VL600 wants IPv6 packets to have an IPv4 ethertype > > - * Check if this is an IPv6 packet, and set the ethertype > > - * to 0x800 > > - */ > > - if ((skb->data[sizeof(struct vl600_pkt_hdr *) + 0x22] & 0xf0) == 0x60) { > > - skb->data[sizeof(struct vl600_pkt_hdr *) + 0x20] = 0x08; > > - skb->data[sizeof(struct vl600_pkt_hdr *) + 0x21] = 0; > > - } > > - > > return skb; > > } > > > > static const struct driver_info vl600_info = { > > .description = "LG VL600 modem", > > - .flags = FLAG_ETHER | FLAG_RX_ASSEMBLE, > > + .flags = FLAG_RX_ASSEMBLE | FLAG_WWAN, > > .bind = vl600_bind, > > .unbind = vl600_unbind, > > .status = usbnet_cdc_status, > > > -- Mark Kamichoff prox@prolixium.com http://www.prolixium.com/