From c40a2c8817e42273a4627c48c884b805475a733f Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Mon, 7 Sep 2015 16:05:38 +0200 Subject: [PATCH] CDC: common parser for extra headers CDC drivers all implement their own parser for the extra headers. This patch fixes the code duplication introducing a single common parser in usbnet. Signed-off-by: Oliver Neukum Signed-off-by: David S. Miller --- drivers/net/usb/usbnet.c | 138 +++++++++++++++++++++++++++++++++++++++ include/linux/usb/cdc.h | 47 +++++++++++++ 2 files changed, 185 insertions(+) create mode 100644 include/linux/usb/cdc.h diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index b4cf10781348..060918f49fea 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include #include @@ -1962,6 +1963,143 @@ out: return err; } +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); + /* * The function can't be called inside suspend/resume callback, * otherwise deadlock will be caused. diff --git a/include/linux/usb/cdc.h b/include/linux/usb/cdc.h new file mode 100644 index 000000000000..cd8f2e1c3bdf --- /dev/null +++ b/include/linux/usb/cdc.h @@ -0,0 +1,47 @@ +/* + * USB CDC common helpers + * + * Copyright (c) 2015 Oliver Neukum + * + * 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 + +/* + * inofficial magic numbers + */ + +#define CDC_PHONET_MAGIC_NUMBER 0xAB + +/* + * parsing CDC headers + */ + +struct usb_cdc_parsed_header { + struct usb_cdc_union_desc *usb_cdc_union_desc; + struct usb_cdc_header_desc *usb_cdc_header_desc; + + struct usb_cdc_call_mgmt_descriptor *usb_cdc_call_mgmt_descriptor; + struct usb_cdc_acm_descriptor *usb_cdc_acm_descriptor; + struct usb_cdc_country_functional_desc *usb_cdc_country_functional_desc; + struct usb_cdc_network_terminal_desc *usb_cdc_network_terminal_desc; + struct usb_cdc_ether_desc *usb_cdc_ether_desc; + struct usb_cdc_dmm_desc *usb_cdc_dmm_desc; + struct usb_cdc_mdlm_desc *usb_cdc_mdlm_desc; + struct usb_cdc_mdlm_detail_desc *usb_cdc_mdlm_detail_desc; + struct usb_cdc_obex_desc *usb_cdc_obex_desc; + struct usb_cdc_ncm_desc *usb_cdc_ncm_desc; + struct usb_cdc_mbim_desc *usb_cdc_mbim_desc; + struct usb_cdc_mbim_extended_desc *usb_cdc_mbim_extended_desc; + + bool phonet_magic_present; +}; + + +int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr, + struct usb_interface *intf, + u8 *buffer, + int buflen);