From d8b37fe189d5cacf9bac8162d25c58c1a6890a6c Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Wed, 26 Jan 2022 22:02:24 +0100
Subject: [PATCH] Wrap libusb_device

Introduce a structure to wrap a libusb_device and expose its descriptor
data read during discovery.

PR #2974 <https://github.com/Genymobile/scrcpy/pull/2974>
---
 app/src/scrcpy.c  | 13 +++++++++----
 app/src/usb/usb.c | 47 +++++++++++++++++++++++++++++++++++------------
 app/src/usb/usb.h | 17 +++++++++++++++--
 3 files changed, 59 insertions(+), 18 deletions(-)

diff --git a/app/src/scrcpy.c b/app/src/scrcpy.c
index 9039eede..7d58b0f1 100644
--- a/app/src/scrcpy.c
+++ b/app/src/scrcpy.c
@@ -432,16 +432,21 @@ scrcpy(struct scrcpy_options *options) {
             }
 
             assert(serial);
-            libusb_device *device = sc_usb_find_device(&s->usb, serial);
-            if (!device) {
+            struct sc_usb_device usb_device;
+            ok = sc_usb_find_device(&s->usb, serial, &usb_device);
+            if (!ok) {
                 LOGE("Could not find USB device %s", serial);
                 sc_usb_destroy(&s->usb);
                 sc_acksync_destroy(&s->acksync);
                 goto aoa_hid_end;
             }
 
-            ok = sc_usb_connect(&s->usb, device);
-            libusb_unref_device(device);
+            LOGI("USB device: %s (%04" PRIx16 ":%04" PRIx16 ") %s %s",
+                 usb_device.serial, usb_device.vid, usb_device.pid,
+                 usb_device.manufacturer, usb_device.product);
+
+            ok = sc_usb_connect(&s->usb, usb_device.device);
+            sc_usb_device_destroy(&usb_device);
             if (!ok) {
                 LOGE("Failed to connect to USB device %s", serial);
                 sc_usb_destroy(&s->usb);
diff --git a/app/src/usb/usb.c b/app/src/usb/usb.c
index 459aefc0..9d5f35be 100644
--- a/app/src/usb/usb.c
+++ b/app/src/usb/usb.c
@@ -30,7 +30,8 @@ read_string(libusb_device_handle *handle, uint8_t desc_index) {
 }
 
 static bool
-accept_device(libusb_device *device, const char *serial) {
+accept_device(libusb_device *device, const char *serial,
+              struct sc_usb_device *out) {
     // Do not log any USB error in this function, it is expected that many USB
     // devices available on the computer have permission restrictions
 
@@ -47,39 +48,61 @@ accept_device(libusb_device *device, const char *serial) {
     }
 
     char *device_serial = read_string(handle, desc.iSerialNumber);
-    libusb_close(handle);
     if (!device_serial) {
+        libusb_close(handle);
         return false;
     }
 
     bool matches = !strcmp(serial, device_serial);
-    free(device_serial);
-    return matches;
+    if (!matches) {
+        free(device_serial);
+        libusb_close(handle);
+        return false;
+    }
+
+    out->device = libusb_ref_device(device);
+    out->serial = device_serial;
+    out->vid = desc.idVendor;
+    out->pid = desc.idProduct;
+    out->manufacturer = read_string(handle, desc.iManufacturer);
+    out->product = read_string(handle, desc.iProduct);
+
+    libusb_close(handle);
+
+    return true;
+}
+
+void
+sc_usb_device_destroy(struct sc_usb_device *usb_device) {
+    libusb_unref_device(usb_device->device);
+    free(usb_device->serial);
+    free(usb_device->manufacturer);
+    free(usb_device->product);
 }
 
-libusb_device *
-sc_usb_find_device(struct sc_usb *usb, const char *serial) {
+bool
+sc_usb_find_device(struct sc_usb *usb, const char *serial,
+                   struct sc_usb_device *out) {
     assert(serial);
 
     libusb_device **list;
-    libusb_device *result = NULL;
     ssize_t count = libusb_get_device_list(usb->context, &list);
     if (count < 0) {
         log_libusb_error((enum libusb_error) count);
-        return NULL;
+        return false;
     }
 
     for (size_t i = 0; i < (size_t) count; ++i) {
         libusb_device *device = list[i];
 
-        if (accept_device(device, serial)) {
-            result = libusb_ref_device(device);
-            break;
+        if (accept_device(device, serial, out)) {
+            libusb_free_device_list(list, 1);
+            return true;
         }
     }
 
     libusb_free_device_list(list, 1);
-    return result;
+    return false;
 }
 
 static libusb_device_handle *
diff --git a/app/src/usb/usb.h b/app/src/usb/usb.h
index 0ab7ce90..ea6e5514 100644
--- a/app/src/usb/usb.h
+++ b/app/src/usb/usb.h
@@ -11,14 +11,27 @@ struct sc_usb {
     libusb_device_handle *handle;
 };
 
+struct sc_usb_device {
+    libusb_device *device;
+    char *serial;
+    char *manufacturer;
+    char *product;
+    uint16_t vid;
+    uint16_t pid;
+};
+
+void
+sc_usb_device_destroy(struct sc_usb_device *usb_device);
+
 bool
 sc_usb_init(struct sc_usb *usb);
 
 void
 sc_usb_destroy(struct sc_usb *usb);
 
-libusb_device *
-sc_usb_find_device(struct sc_usb *usb, const char *serial);
+bool
+sc_usb_find_device(struct sc_usb *usb, const char *serial,
+                   struct sc_usb_device *out);
 
 bool
 sc_usb_connect(struct sc_usb *usb, libusb_device *device);