Windows: Try alternative methods to query port number
This commit is similar to #634 but I think it offers a better approach. The commit adds two more methods for querying the port number, in addition to the existing SPDRP_ADDRESS method, which may not actually return the port number when using USB drivers other than the Microsoft driver.
The first method uses SPDRP_LOCATION_INFORMATION, which may return a port in a format similar to "Port_#0002.Hub_#000D".
The second method uses SPDRP_LOCATION_PATHS, which returns the device location in a format similar to "PCIROOT(B2)#PCI(0300)#PCI(0000)#USBROOT(0)#USB(1)#USB(2)#USBMI(3)", where the port number is the number within the last "#USB()" token.
If both methods fail, SPDRP_ADDRESS is still used as a fallback.
Closes #867
Signed-off-by: Nathan Hjelm <hjelmn@google.com>
diff --git a/libusb/os/windows_winusb.c b/libusb/os/windows_winusb.c
index 877a2ab..e1e599c 100644
--- a/libusb/os/windows_winusb.c
+++ b/libusb/os/windows_winusb.c
@@ -1223,6 +1223,47 @@
return LIBUSB_SUCCESS;
}
+static bool get_dev_port_number(HDEVINFO dev_info, SP_DEVINFO_DATA *dev_info_data, DWORD *port_nr)
+{
+ char buffer[MAX_KEY_LENGTH];
+ DWORD size;
+
+ // First try SPDRP_LOCATION_INFORMATION, which returns a REG_SZ. The string *may* have a format
+ // similar to "Port_#0002.Hub_#000D", in which case we can extract the port number. However, we
+ // cannot extract the port if the returned string does not follow this format.
+ if (pSetupDiGetDeviceRegistryPropertyA(dev_info, dev_info_data, SPDRP_LOCATION_INFORMATION,
+ NULL, (PBYTE)buffer, sizeof(buffer), NULL)) {
+ // Check for the required format.
+ if (strncmp(buffer, "Port_#", 6) == 0) {
+ *port_nr = atoi(buffer + 6);
+ return true;
+ }
+ }
+
+ // Next try SPDRP_LOCATION_PATHS, which returns a REG_MULTI_SZ (but we only examine the first
+ // string in it). Each path has a format similar to,
+ // "PCIROOT(B2)#PCI(0300)#PCI(0000)#USBROOT(0)#USB(1)#USB(2)#USBMI(3)", and the port number is
+ // the number within the last "USB(x)" token.
+ if (pSetupDiGetDeviceRegistryPropertyA(dev_info, dev_info_data, SPDRP_LOCATION_PATHS,
+ NULL, (PBYTE)buffer, sizeof(buffer), NULL)) {
+ // Find the last "#USB(x)" substring
+ for (char *token = strrchr(buffer, '#'); token != NULL; token = strrchr(buffer, '#')) {
+ if (strncmp(token, "#USB(", 5) == 0) {
+ *port_nr = atoi(token + 5);
+ return true;
+ }
+ // Shorten the string and try again.
+ *token = '\0';
+ }
+ }
+
+ // Lastly, try SPDRP_ADDRESS, which returns a REG_DWORD. The address *may* be the port number,
+ // which is true for the Microsoft driver but may not be true for other drivers. However, we
+ // have no other options here but to accept what it returns.
+ return pSetupDiGetDeviceRegistryPropertyA(dev_info, dev_info_data, SPDRP_ADDRESS,
+ NULL, (PBYTE)port_nr, sizeof(*port_nr), &size) && (size == sizeof(*port_nr));
+}
+
static int enumerate_hcd_root_hub(struct libusb_context *ctx, const char *dev_id,
uint8_t bus_number, DEVINST devinst)
{
@@ -1747,10 +1788,8 @@
r = enumerate_hcd_root_hub(ctx, dev_id, (uint8_t)(i + 1), dev_info_data.DevInst);
break;
case GEN_PASS:
- // The SPDRP_ADDRESS for USB devices is the device port number on the hub
port_nr = 0;
- if (!pSetupDiGetDeviceRegistryPropertyA(*dev_info, &dev_info_data, SPDRP_ADDRESS,
- NULL, (PBYTE)&port_nr, sizeof(port_nr), &size) || (size != sizeof(port_nr)))
+ if (!get_dev_port_number(*dev_info, &dev_info_data, &port_nr))
usbi_warn(ctx, "could not retrieve port number for device '%s': %s", dev_id, windows_error_str(0));
r = init_device(dev, parent_dev, (uint8_t)port_nr, dev_info_data.DevInst);
if (r == LIBUSB_SUCCESS) {
diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index 53d05fe..6524fe2 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11621
+#define LIBUSB_NANO 11622
