diff options
Diffstat (limited to 'compat/backport-4.8.c')
| -rw-r--r-- | compat/backport-4.8.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/compat/backport-4.8.c b/compat/backport-4.8.c new file mode 100644 index 0000000..7d05644 --- /dev/null +++ b/compat/backport-4.8.c @@ -0,0 +1,146 @@ +/* + * Copyright(c) 2017 Intel Deutschland GmbH + * + * Backport functionality introduced in Linux 4.8. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/usb.h> +#include <linux/usb/cdc.h> + +int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr, + struct usb_interface *intf, + u8 *buffer, int buflen) +{ + /* duplicates are ignored */ + struct usb_cdc_union_desc *union_header = NULL; + + /* duplicates are not tolerated */ + struct usb_cdc_header_desc *header = NULL; + struct usb_cdc_ether_desc *ether = NULL; + struct usb_cdc_mdlm_detail_desc *detail = NULL; + struct usb_cdc_mdlm_desc *desc = NULL; + + unsigned int elength; + int cnt = 0; + + memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header)); + hdr->phonet_magic_present = false; + while (buflen > 0) { + elength = buffer[0]; + if (!elength) { + dev_err(&intf->dev, "skipping garbage byte\n"); + elength = 1; + goto next_desc; + } + if (buffer[1] != USB_DT_CS_INTERFACE) { + dev_err(&intf->dev, "skipping garbage\n"); + goto next_desc; + } + + switch (buffer[2]) { + case USB_CDC_UNION_TYPE: /* we've found it */ + if (elength < sizeof(struct usb_cdc_union_desc)) + goto next_desc; + if (union_header) { + dev_err(&intf->dev, "More than one union descriptor, skipping ...\n"); + goto next_desc; + } + union_header = (struct usb_cdc_union_desc *)buffer; + break; + case USB_CDC_COUNTRY_TYPE: + if (elength < sizeof(struct usb_cdc_country_functional_desc)) + goto next_desc; + hdr->usb_cdc_country_functional_desc = + (struct usb_cdc_country_functional_desc *)buffer; + break; + case USB_CDC_HEADER_TYPE: + if (elength != sizeof(struct usb_cdc_header_desc)) + goto next_desc; + if (header) + return -EINVAL; + header = (struct usb_cdc_header_desc *)buffer; + break; + case USB_CDC_ACM_TYPE: + if (elength < sizeof(struct usb_cdc_acm_descriptor)) + goto next_desc; + hdr->usb_cdc_acm_descriptor = + (struct usb_cdc_acm_descriptor *)buffer; + break; + case USB_CDC_ETHERNET_TYPE: + if (elength != sizeof(struct usb_cdc_ether_desc)) + goto next_desc; + if (ether) + return -EINVAL; + ether = (struct usb_cdc_ether_desc *)buffer; + break; + case USB_CDC_CALL_MANAGEMENT_TYPE: + if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor)) + goto next_desc; + hdr->usb_cdc_call_mgmt_descriptor = + (struct usb_cdc_call_mgmt_descriptor *)buffer; + break; + case USB_CDC_DMM_TYPE: + if (elength < sizeof(struct usb_cdc_dmm_desc)) + goto next_desc; + hdr->usb_cdc_dmm_desc = + (struct usb_cdc_dmm_desc *)buffer; + break; + case USB_CDC_MDLM_TYPE: + if (elength < sizeof(struct usb_cdc_mdlm_desc *)) + goto next_desc; + if (desc) + return -EINVAL; + desc = (struct usb_cdc_mdlm_desc *)buffer; + break; + case USB_CDC_MDLM_DETAIL_TYPE: + if (elength < sizeof(struct usb_cdc_mdlm_detail_desc *)) + goto next_desc; + if (detail) + return -EINVAL; + detail = (struct usb_cdc_mdlm_detail_desc *)buffer; + break; + case USB_CDC_NCM_TYPE: + if (elength < sizeof(struct usb_cdc_ncm_desc)) + goto next_desc; + hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer; + break; + case USB_CDC_MBIM_TYPE: + if (elength < sizeof(struct usb_cdc_mbim_desc)) + goto next_desc; + + hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer; + break; + case USB_CDC_MBIM_EXTENDED_TYPE: + if (elength < sizeof(struct usb_cdc_mbim_extended_desc)) + break; + hdr->usb_cdc_mbim_extended_desc = + (struct usb_cdc_mbim_extended_desc *)buffer; + break; + case CDC_PHONET_MAGIC_NUMBER: + hdr->phonet_magic_present = true; + break; + default: + /* + * there are LOTS more CDC descriptors that + * could legitimately be found here. + */ + dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n", + buffer[2], elength); + goto next_desc; + } + cnt++; +next_desc: + buflen -= elength; + buffer += elength; + } + hdr->usb_cdc_union_desc = union_header; + hdr->usb_cdc_header_desc = header; + hdr->usb_cdc_mdlm_detail_desc = detail; + hdr->usb_cdc_mdlm_desc = desc; + hdr->usb_cdc_ether_desc = ether; + return cnt; +} +EXPORT_SYMBOL_GPL(cdc_parse_cdc_header); |