From 823bd3433424aa959499e6fd8f2da842430a8d42 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Mon, 7 Sep 2015 16:05:40 +0200 Subject: [PATCH] cdc-ether: switch to common CDC parser This patch uses the common parser to parse extra CDC headers in order to reduce code duplication. Signed-off-by: Oliver Neukum Signed-off-by: David S. Miller --- drivers/net/usb/cdc_ether.c | 230 +++++++++++++----------------------- 1 file changed, 81 insertions(+), 149 deletions(-) diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c index 35a2bffe848a..c78d3cb1b464 100644 --- a/drivers/net/usb/cdc_ether.c +++ b/drivers/net/usb/cdc_ether.c @@ -112,8 +112,7 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) int rndis; bool android_rndis_quirk = false; struct usb_driver *driver = driver_of(intf); - struct usb_cdc_mdlm_desc *desc = NULL; - struct usb_cdc_mdlm_detail_desc *detail = NULL; + struct usb_cdc_parsed_header header; if (sizeof(dev->data) < sizeof(*info)) return -EDOM; @@ -155,156 +154,89 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) memset(info, 0, sizeof(*info)); info->control = intf; - while (len > 3) { - if (buf[1] != USB_DT_CS_INTERFACE) - goto next_desc; - - /* use bDescriptorSubType to identify the CDC descriptors. - * We expect devices with CDC header and union descriptors. - * For CDC Ethernet we need the ethernet descriptor. - * For RNDIS, ignore two (pointless) CDC modem descriptors - * in favor of a complicated OID-based RPC scheme doing what - * CDC Ethernet achieves with a simple descriptor. - */ - switch (buf[2]) { - case USB_CDC_HEADER_TYPE: - if (info->header) { - dev_dbg(&intf->dev, "extra CDC header\n"); - goto bad_desc; - } - info->header = (void *) buf; - if (info->header->bLength != sizeof(*info->header)) { - dev_dbg(&intf->dev, "CDC header len %u\n", - info->header->bLength); - goto bad_desc; - } - break; - case USB_CDC_ACM_TYPE: - /* paranoia: disambiguate a "real" vendor-specific - * modem interface from an RNDIS non-modem. - */ - if (rndis) { - struct usb_cdc_acm_descriptor *acm; - - acm = (void *) buf; - if (acm->bmCapabilities) { - dev_dbg(&intf->dev, - "ACM capabilities %02x, " - "not really RNDIS?\n", - acm->bmCapabilities); - goto bad_desc; - } - } - break; - case USB_CDC_UNION_TYPE: - if (info->u) { - dev_dbg(&intf->dev, "extra CDC union\n"); - goto bad_desc; - } - info->u = (void *) buf; - if (info->u->bLength != sizeof(*info->u)) { - dev_dbg(&intf->dev, "CDC union len %u\n", - info->u->bLength); - goto bad_desc; - } - - /* we need a master/control interface (what we're - * probed with) and a slave/data interface; union - * descriptors sort this all out. - */ - info->control = usb_ifnum_to_if(dev->udev, - info->u->bMasterInterface0); - info->data = usb_ifnum_to_if(dev->udev, - info->u->bSlaveInterface0); - if (!info->control || !info->data) { - dev_dbg(&intf->dev, - "master #%u/%p slave #%u/%p\n", - info->u->bMasterInterface0, - info->control, - info->u->bSlaveInterface0, - info->data); - /* fall back to hard-wiring for RNDIS */ - if (rndis) { - android_rndis_quirk = true; - goto next_desc; - } - goto bad_desc; - } - if (info->control != intf) { - dev_dbg(&intf->dev, "bogus CDC Union\n"); - /* Ambit USB Cable Modem (and maybe others) - * interchanges master and slave interface. - */ - if (info->data == intf) { - info->data = info->control; - info->control = intf; - } else - goto bad_desc; - } - - /* some devices merge these - skip class check */ - if (info->control == info->data) - goto next_desc; - - /* a data interface altsetting does the real i/o */ - d = &info->data->cur_altsetting->desc; - if (d->bInterfaceClass != USB_CLASS_CDC_DATA) { - dev_dbg(&intf->dev, "slave class %u\n", - d->bInterfaceClass); - goto bad_desc; - } - break; - case USB_CDC_ETHERNET_TYPE: - if (info->ether) { - dev_dbg(&intf->dev, "extra CDC ether\n"); - goto bad_desc; - } - info->ether = (void *) buf; - if (info->ether->bLength != sizeof(*info->ether)) { - dev_dbg(&intf->dev, "CDC ether len %u\n", - info->ether->bLength); - goto bad_desc; - } - dev->hard_mtu = le16_to_cpu( - info->ether->wMaxSegmentSize); - /* because of Zaurus, we may be ignoring the host - * side link address we were given. - */ - break; - case USB_CDC_MDLM_TYPE: - if (desc) { - dev_dbg(&intf->dev, "extra MDLM descriptor\n"); - goto bad_desc; - } - - desc = (void *)buf; - - if (desc->bLength != sizeof(*desc)) - goto bad_desc; - - if (memcmp(&desc->bGUID, mbm_guid, 16)) - goto bad_desc; - break; - case USB_CDC_MDLM_DETAIL_TYPE: - if (detail) { - dev_dbg(&intf->dev, "extra MDLM detail descriptor\n"); - goto bad_desc; - } - - detail = (void *)buf; - - if (detail->bGuidDescriptorType == 0) { - if (detail->bLength < (sizeof(*detail) + 1)) - goto bad_desc; - } else - goto bad_desc; - break; + + cdc_parse_cdc_header(&header, intf, buf, len); + + info->u = header.usb_cdc_union_desc; + info->header = header.usb_cdc_header_desc; + info->ether = header.usb_cdc_ether_desc; + /* we need a master/control interface (what we're + * probed with) and a slave/data interface; union + * descriptors sort this all out. + */ + info->control = usb_ifnum_to_if(dev->udev, + info->u->bMasterInterface0); + info->data = usb_ifnum_to_if(dev->udev, + info->u->bSlaveInterface0); + if (!info->control || !info->data) { + dev_dbg(&intf->dev, + "master #%u/%p slave #%u/%p\n", + info->u->bMasterInterface0, + info->control, + info->u->bSlaveInterface0, + info->data); + /* fall back to hard-wiring for RNDIS */ + if (rndis) { + android_rndis_quirk = true; + goto skip; } -next_desc: - len -= buf[0]; /* bLength */ - buf += buf[0]; + goto bad_desc; + } + if (info->control != intf) { + dev_dbg(&intf->dev, "bogus CDC Union\n"); + /* Ambit USB Cable Modem (and maybe others) + * interchanges master and slave interface. + */ + if (info->data == intf) { + info->data = info->control; + info->control = intf; + } else + goto bad_desc; + } + + /* some devices merge these - skip class check */ + if (info->control == info->data) + goto skip; + + /* a data interface altsetting does the real i/o */ + d = &info->data->cur_altsetting->desc; + if (d->bInterfaceClass != USB_CLASS_CDC_DATA) { + dev_dbg(&intf->dev, "slave class %u\n", + d->bInterfaceClass); + goto bad_desc; + } +skip: + if ( rndis && + header.usb_cdc_acm_descriptor && + header.usb_cdc_acm_descriptor->bmCapabilities) { + dev_dbg(&intf->dev, + "ACM capabilities %02x, not really RNDIS?\n", + header.usb_cdc_acm_descriptor->bmCapabilities); + goto bad_desc; } + if (header.usb_cdc_ether_desc) { + dev->hard_mtu = le16_to_cpu(info->ether->wMaxSegmentSize); + /* because of Zaurus, we may be ignoring the host + * side link address we were given. + */ + } + + if (header.usb_cdc_mdlm_desc && + memcmp(header.usb_cdc_mdlm_desc->bGUID, mbm_guid, 16)) { + dev_dbg(&intf->dev, "GUID doesn't match\n"); + goto bad_desc; + } + + if (header.usb_cdc_mdlm_detail_desc && + header.usb_cdc_mdlm_detail_desc->bLength < + (sizeof(struct usb_cdc_mdlm_detail_desc) + 1)) { + dev_dbg(&intf->dev, "Descriptor too short\n"); + goto bad_desc; + } + + + /* Microsoft ActiveSync based and some regular RNDIS devices lack the * CDC descriptors, so we'll hard-wire the interfaces and not check * for descriptors. -- 2.20.1