usb.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include <errno.h>
   5 #include <libusb.h>
   6
   7
   8
   9
  10 static int ncusb_match_string(libusb_device_handle *dev, int index, const char* string)
  11 {
  12         unsigned char tmp[256];
  13         libusb_get_string_descriptor_ascii(dev, index, tmp, 256);
  14         if (string == NULL)
  15                 return 1; /* NULL matches anything */
  16         return (strcmp(string, (char*) tmp)==0);
  17 }
  18
  19
  20 struct libusb_device_handle *ncusb_find_and_open(struct libusb_context *ctx,
  21                                           int vendor, int product,
  22                                           const char *vendor_name,
  23                                           const char *product_name,
  24                                           const char *serial)
  25 {
  26         libusb_device_handle *found = NULL;
  27         libusb_device **list;
  28         ssize_t cnt = libusb_get_device_list(ctx, &list);
  29         ssize_t i = 0;
  30
  31         if (cnt < 0){
  32                 return NULL;
  33         }
  34
  35         for(i = 0; i < cnt; i++) {
  36                 libusb_device *device = list[i];
  37                 struct libusb_device_descriptor desc;
  38                 libusb_device_handle *handle;
  39
  40                 if ( libusb_get_device_descriptor( device, &desc ) )
  41                         continue;
  42
  43                 if ( desc.idVendor == vendor && desc.idProduct == product ) {
  44                         if ( libusb_open(device, &handle) )
  45                                 continue;
  46
  47                         if (ncusb_match_string(handle, desc.iManufacturer, vendor_name) &&
  48                             ncusb_match_string(handle, desc.iProduct,     product_name) &&
  49                             ncusb_match_string(handle, desc.iSerialNumber, serial) )
  50                         {
  51                                 found = handle;
  52                         }
  53                 }
  54
  55                 if (found)
  56                         break;
  57
  58         }
  59         libusb_free_device_list(list, 1);
  60
  61         return found;
  62 }
  63
  64
  65 void check_handle(libusb_device_handle **h, int vid, int pid, const char* manuf, const char* product, const char* serial)
  66 {
  67         static libusb_context *ctx=NULL;
  68
  69         if (*h)
  70                 return;
  71         if (!ctx)
  72                 libusb_init(&ctx);
  73         libusb_set_debug(ctx, LIBUSB_LOG_LEVEL_WARNING);
  74         *h = ncusb_find_and_open(ctx, vid, pid, manuf, product, serial);
  75         if (!(*h)) {
  76                 fprintf(stderr, "No USB device %04x:%04x found ;(\n", vid, pid);
  77                 exit(1);
  78         }
  79 }