hw/usb/desc-msos.c

   1 #include "qemu/osdep.h"
   2 #include "hw/usb.h"
   3 #include "desc.h"
   4
   5 /*
   6  * Microsoft OS Descriptors
   7  *
   8  * Windows tries to fetch some special descriptors with information
   9  * specifically for windows.  Presence is indicated using a special
  10  * string @ index 0xee.  There are two kinds of descriptors:
  11  *
  12  * compatid descriptor
  13  *   Used to bind drivers, if usb class isn't specific enough.
  14  *   Used for PTP/MTP for example (both share the same usb class).
  15  *
  16  * properties descriptor
  17  *   Does carry registry entries.  They show up in
  18  *   HLM\SYSTEM\CurrentControlSet\Enum\USB\<devid>\<serial>\Device Parameters
  19  *
  20  * Note that Windows caches the stuff it got in the registry, so when
  21  * playing with this you have to delete registry subtrees to make
  22  * windows query the device again:
  23  *   HLM\SYSTEM\CurrentControlSet\Control\usbflags
  24  *   HLM\SYSTEM\CurrentControlSet\Enum\USB
  25  * Windows will complain it can't delete entries on the second one.
  26  * It has deleted everything it had permissions too, which is enough
  27  * as this includes "Device Parameters".
  28  *
  29  * http://msdn.microsoft.com/en-us/library/windows/hardware/ff537430.aspx
  30  *
  31  */
  32
  33 /* ------------------------------------------------------------------ */
  34
  35 typedef struct msos_compat_hdr {
  36     uint32_t dwLength;
  37     uint8_t  bcdVersion_lo;
  38     uint8_t  bcdVersion_hi;
  39     uint8_t  wIndex_lo;
  40     uint8_t  wIndex_hi;
  41     uint8_t  bCount;
  42     uint8_t  reserved[7];
  43 } QEMU_PACKED msos_compat_hdr;
  44
  45 typedef struct msos_compat_func {
  46     uint8_t  bFirstInterfaceNumber;
  47     uint8_t  reserved_1;
  48     char     compatibleId[8];
  49     uint8_t  subCompatibleId[8];
  50     uint8_t  reserved_2[6];
  51 } QEMU_PACKED msos_compat_func;
  52
  53 static int usb_desc_msos_compat(const USBDesc *desc, uint8_t *dest)
  54 {
  55     msos_compat_hdr *hdr = (void *)dest;
  56     msos_compat_func *func;
  57     int length = sizeof(*hdr);
  58     int count = 0;
  59
  60     func = (void *)(dest + length);
  61     func->bFirstInterfaceNumber = 0;
  62     func->reserved_1 = 0x01;
  63     if (desc->msos->CompatibleID) {
  64         snprintf(func->compatibleId, sizeof(func->compatibleId),
  65                  "%s", desc->msos->CompatibleID);
  66     }
  67     length += sizeof(*func);
  68     count++;
  69
  70     hdr->dwLength      = cpu_to_le32(length);
  71     hdr->bcdVersion_lo = 0x00;
  72     hdr->bcdVersion_hi = 0x01;
  73     hdr->wIndex_lo     = 0x04;
  74     hdr->wIndex_hi     = 0x00;
  75     hdr->bCount        = count;
  76     return length;
  77 }
  78
  79 /* ------------------------------------------------------------------ */
  80
  81 typedef struct msos_prop_hdr {
  82     uint32_t dwLength;
  83     uint8_t  bcdVersion_lo;
  84     uint8_t  bcdVersion_hi;
  85     uint8_t  wIndex_lo;
  86     uint8_t  wIndex_hi;
  87     uint8_t  wCount_lo;
  88     uint8_t  wCount_hi;
  89 } QEMU_PACKED msos_prop_hdr;
  90
  91 typedef struct msos_prop {
  92     uint32_t dwLength;
  93     uint32_t dwPropertyDataType;
  94     uint8_t  dwPropertyNameLength_lo;
  95     uint8_t  dwPropertyNameLength_hi;
  96     uint8_t  bPropertyName[];
  97 } QEMU_PACKED msos_prop;
  98
  99 typedef struct msos_prop_data {
 100     uint32_t dwPropertyDataLength;
 101     uint8_t  bPropertyData[];
 102 } QEMU_PACKED msos_prop_data;
 103
 104 typedef enum msos_prop_type {
 105     MSOS_REG_SZ        = 1,
 106     MSOS_REG_EXPAND_SZ = 2,
 107     MSOS_REG_BINARY    = 3,
 108     MSOS_REG_DWORD_LE  = 4,
 109     MSOS_REG_DWORD_BE  = 5,
 110     MSOS_REG_LINK      = 6,
 111     MSOS_REG_MULTI_SZ  = 7,
 112 } msos_prop_type;
 113
 114 static int usb_desc_msos_prop_name(struct msos_prop *prop,
 115                                    const wchar_t *name)
 116 {
 117     int length = wcslen(name) + 1;
 118     int i;
 119
 120     prop->dwPropertyNameLength_lo = usb_lo(length*2);
 121     prop->dwPropertyNameLength_hi = usb_hi(length*2);
 122     for (i = 0; i < length; i++) {
 123         prop->bPropertyName[i*2]   = usb_lo(name[i]);
 124         prop->bPropertyName[i*2+1] = usb_hi(name[i]);
 125     }
 126     return length*2;
 127 }
 128
 129 static int usb_desc_msos_prop_str(uint8_t *dest, msos_prop_type type,
 130                                   const wchar_t *name, const wchar_t *value)
 131 {
 132     struct msos_prop *prop = (void *)dest;
 133     struct msos_prop_data *data;
 134     int length = sizeof(*prop);
 135     int i, vlen = wcslen(value) + 1;
 136
 137     prop->dwPropertyDataType = cpu_to_le32(type);
 138     length += usb_desc_msos_prop_name(prop, name);
 139     data = (void *)(dest + length);
 140
 141     data->dwPropertyDataLength = cpu_to_le32(vlen*2);
 142     length += sizeof(*prop);
 143
 144     for (i = 0; i < vlen; i++) {
 145         data->bPropertyData[i*2]   = usb_lo(value[i]);
 146         data->bPropertyData[i*2+1] = usb_hi(value[i]);
 147     }
 148     length += vlen*2;
 149
 150     prop->dwLength = cpu_to_le32(length);
 151     return length;
 152 }
 153
 154 static int usb_desc_msos_prop_dword(uint8_t *dest, const wchar_t *name,
 155                                     uint32_t value)
 156 {
 157     struct msos_prop *prop = (void *)dest;
 158     struct msos_prop_data *data;
 159     int length = sizeof(*prop);
 160
 161     prop->dwPropertyDataType = cpu_to_le32(MSOS_REG_DWORD_LE);
 162     length += usb_desc_msos_prop_name(prop, name);
 163     data = (void *)(dest + length);
 164
 165     data->dwPropertyDataLength = cpu_to_le32(4);
 166     data->bPropertyData[0] = (value)       & 0xff;
 167     data->bPropertyData[1] = (value >>  8) & 0xff;
 168     data->bPropertyData[2] = (value >> 16) & 0xff;
 169     data->bPropertyData[3] = (value >> 24) & 0xff;
 170     length += sizeof(*prop) + 4;
 171
 172     prop->dwLength = cpu_to_le32(length);
 173     return length;
 174 }
 175
 176 static int usb_desc_msos_prop(const USBDesc *desc, uint8_t *dest)
 177 {
 178     msos_prop_hdr *hdr = (void *)dest;
 179     int length = sizeof(*hdr);
 180     int count = 0;
 181
 182     if (desc->msos->Label) {
 183         /*
 184          * Given as example in the specs.  Haven't figured yet where
 185          * this label shows up in the windows gui.
 186          */
 187         length += usb_desc_msos_prop_str(dest+length, MSOS_REG_SZ,
 188                                          L"Label", desc->msos->Label);
 189         count++;
 190     }
 191
 192     if (desc->msos->SelectiveSuspendEnabled) {
 193         /*
 194          * Signaling remote wakeup capability in the standard usb
 195          * descriptors isn't enough to make windows actually use it.
 196          * This is the "Yes, we really mean it" registry entry to flip
 197          * the switch in the windows drivers.
 198          */
 199         length += usb_desc_msos_prop_dword(dest+length,
 200                                            L"SelectiveSuspendEnabled", 1);
 201         count++;
 202     }
 203
 204     hdr->dwLength      = cpu_to_le32(length);
 205     hdr->bcdVersion_lo = 0x00;
 206     hdr->bcdVersion_hi = 0x01;
 207     hdr->wIndex_lo     = 0x05;
 208     hdr->wIndex_hi     = 0x00;
 209     hdr->wCount_lo     = usb_lo(count);
 210     hdr->wCount_hi     = usb_hi(count);
 211     return length;
 212 }
 213
 214 /* ------------------------------------------------------------------ */
 215
 216 int usb_desc_msos(const USBDesc *desc,  USBPacket *p,
 217                   int index, uint8_t *dest, size_t len)
 218 {
 219     void *buf = g_malloc0(4096);
 220     int length = 0;
 221
 222     switch (index) {
 223     case 0x0004:
 224         length = usb_desc_msos_compat(desc, buf);
 225         break;
 226     case 0x0005:
 227         length = usb_desc_msos_prop(desc, buf);
 228         break;
 229     }
 230
 231     if (length > len) {
 232         length = len;
 233     }
 234     memcpy(dest, buf, length);
 235     g_free(buf);
 236
 237     p->actual_length = length;
 238     return 0;
 239 }