rawhid.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <fcntl.h>
   4 #include <unistd.h>
   5 #include <sys/ioctl.h>
   6 #include <linux/hidraw.h>
   7
   8 typedef unsigned char byte;
   9 typedef unsigned int uns;
  10
  11 static void parse(byte *desc, uns size)
  12 {
  13         byte *end = desc + size;
  14         uns indent = 0;
  15
  16         while (desc < end) {
  17                 uns flags = *desc++;
  18                 if (flags == 0xfe) {
  19                         printf("FATAL: Unsupported long item found.\n");
  20                         return;
  21                 }
  22                 if ((flags & 0x0c) == 0x0c) {
  23                         printf("FATAL: Unsupported item type 3.\n");
  24                         return;
  25                 }
  26                 const uns sizes[4] = { 0, 1, 2, 4 };
  27                 uns size = sizes[flags & 3];
  28                 if (desc + size > end) {
  29                         printf("FATAL: Truncated item.\n");
  30                         return;
  31                 }
  32                 uns val = 0;
  33                 for (uns i=0; i<size; i++)
  34                         val |= *desc++ << (8*i);
  35
  36                 printf("%*s%c%x[%d:%08x] ", indent, "", "MGL?"[(flags >> 2) & 3], flags >> 4, size, val);
  37                 switch (flags & ~3) {
  38                         /* Main */
  39                         case 0x80:      printf("Input\n");
  40                                         break;
  41                         case 0x90:      printf("Output\n");
  42                                         break;
  43                         case 0xa0:      printf("Collection (type %d) {\n", val);
  44                                         indent += 4;
  45                                         break;
  46                         case 0xb0:      printf("Feature\n");
  47                                         break;
  48                         case 0xc0:      printf("} EndCollection\n");
  49                                         if (indent > 0)
  50                                                 indent -= 4;
  51                                         else
  52                                                 printf("WARNING: Unbalanced collections!\n");
  53                                         break;
  54
  55                         /* Global */
  56                         case 0x04:      printf("UsagePage %04x\n", val);
  57                                         break;
  58                         case 0x14:      printf("LogicalMin %d\n", val);
  59                                         break;
  60                         case 0x24:      printf("LogicalMax %d\n", val);
  61                                         break;
  62                         case 0x34:      printf("PhysicalMin %d\n", val);
  63                                         break;
  64                         case 0x44:      printf("PhysicalMax %d\n", val);
  65                                         break;
  66                         case 0x54:      printf("UnitExponent\n");
  67                                         break;
  68                         case 0x64:      printf("Unit\n");
  69                                         break;
  70                         case 0x74:      printf("ReportSize %d\n", val);
  71                                         break;
  72                         case 0x84:      printf("ReportID %d\n", val);
  73                                         break;
  74                         case 0x94:      printf("ReportCount %d\n", val);
  75                                         break;
  76                         case 0xa4:      printf("PUSH\n");
  77                                         break;
  78                         case 0xb4:      printf("POP\n");
  79                                         break;
  80
  81                         /* Local */
  82                         case 0x08:      printf("Usage %04x\n", val);
  83                                         break;
  84                         case 0x18:      printf("UsageMin %04x\n", val);
  85                                         break;
  86                         case 0x28:      printf("UsageMax %04x\n", val);
  87                                         break;
  88                         case 0x38:      printf("DesignatorIndex %d\n", val);
  89                                         break;
  90                         case 0x48:      printf("DesignatorMin %d\n", val);
  91                                         break;
  92                         case 0x58:      printf("DesignatorMax %d\n", val);
  93                                         break;
  94                         case 0x78:      printf("StringIndex %d\n", val);
  95                                         break;
  96                         case 0x88:      printf("StringMin %d\n", val);
  97                                         break;
  98                         case 0x98:      printf("StringMax %d\n", val);
  99                                         break;
 100                         case 0xa8:      printf("Delimiter %s\n", (val==0 ? "open" : val==1 ? "close" : "???"));
 101                                         break;
 102
 103                         /* Other */
 104                         default:        printf("?\n");
 105                 }
 106         }
 107
 108         if (indent)
 109                 printf("WARNING: Unbalanced collections!\n");
 110 }
 111
 112 int main(void)
 113 {
 114         int fd = open("/dev/hidraw1", O_RDONLY);
 115         if (fd < 0) {
 116                 fprintf(stderr, "Cannot open hidraw: %m\n");
 117                 return 1;
 118         }
 119
 120         int size;
 121         if (ioctl(fd, HIDIOCGRDESCSIZE, &size) < 0) {
 122                 fprintf(stderr, "Cannot get desc size: %m\n");
 123                 return 1;
 124         }
 125         printf("Detected descriptor size %d\n", size);
 126
 127         struct hidraw_report_descriptor desc;
 128         desc.size = size;
 129         if (ioctl(fd, HIDIOCGRDESC, &desc) < 0) {
 130                 fprintf(stderr, "Cannot get desc contents: %m\n");
 131                 return 1;
 132         }
 133         printf("Read %d bytes\n", desc.size);
 134
 135         struct hidraw_devinfo din;
 136         if (ioctl(fd, HIDIOCGRAWINFO, &din) < 0) {
 137                 fprintf(stderr, "Cannot get raw info: %m\n");
 138                 return 1;
 139         }
 140         printf("bustype: %d, id=%04x:%04x\n", din.bustype, (unsigned short) din.vendor, (unsigned short) din.product);
 141
 142         parse(desc.value, size);
 143         return 0;
 144 }