diff options
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/message.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index ea681f157368..0406a59f0551 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -12,6 +12,7 @@ #include <linux/nls.h> #include <linux/device.h> #include <linux/scatterlist.h> +#include <linux/usb/cdc.h> #include <linux/usb/quirks.h> #include <linux/usb/hcd.h> /* for usbcore internals */ #include <asm/byteorder.h> @@ -2023,3 +2024,155 @@ int usb_driver_set_configuration(struct usb_device *udev, int config) return 0; } EXPORT_SYMBOL_GPL(usb_driver_set_configuration); + +/** + * cdc_parse_cdc_header - parse the extra headers present in CDC devices + * @hdr: the place to put the results of the parsing + * @intf: the interface for which parsing is requested + * @buffer: pointer to the extra headers to be parsed + * @buflen: length of the extra headers + * + * This evaluates the extra headers present in CDC devices which + * bind the interfaces for data and control and provide details + * about the capabilities of the device. + * + * Return: number of descriptors parsed or -EINVAL + * if the header is contradictory beyond salvage + */ + +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(cdc_parse_cdc_header); |
