hw/usb/desc-msos.c

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