[PATCH] Fix udev population of input device USB product IDs

[Chase Douglas]

From: Chase Douglas <chase.douglas at ubuntu.com>

The udev device_added function takes the vendor and model IDs of added
devices and converts them into an attribute that can be matched for by
an InputClass configuration. Currently, the udev mechanism is broken
because it looks for the product ID on evdev event nodes instead of the
input node.

This patch reads the product ID from the PRODUCT property of the parent
of the added device. It has been tested on a bluetooth trackpad and a
builtin touchscreen connected over USB.

Signed-off-by: Chase Douglas <chase.douglas at canonical.com>
---
I don't know if this is correct for USB/bluetooth non-evdev devices. Are
there any? Do we care?

 config/udev.c |   45 ++++++++++++++++++++++++++++-----------------
 1 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/config/udev.c b/config/udev.c
index 9934490..5e60052 100644
--- a/config/udev.c
+++ b/config/udev.c
@@ -58,7 +58,7 @@ device_added(struct udev_device *udev_device)
     char *config_info = NULL;
     const char *syspath;
     const char *tags_prop;
-    const char *usb_vendor = NULL, *usb_model = NULL;
+    int usb_vendor, usb_model;
     const char *key, *value, *tmp;
     InputOption *options = NULL, *tmpo;
     InputAttributes attrs = {};
@@ -94,6 +94,9 @@ device_added(struct udev_device *udev_device)
     parent = udev_device_get_parent(udev_device);
     if (parent) {
         const char *ppath = udev_device_get_devnode(parent);
+        const char *product = udev_device_get_property_value(parent, "PRODUCT");
+        const char *cur;
+        char *next;
 
         name = udev_device_get_sysattr_value(parent, "name");
         LOG_SYSATTR(ppath, "name", name);
@@ -104,7 +107,31 @@ device_added(struct udev_device *udev_device)
 
         attrs.pnp_id = udev_device_get_sysattr_value(parent, "id");
         LOG_SYSATTR(ppath, "id", attrs.pnp_id);
+
+        /* construct USB ID in lowercase hex - "0000:ffff" */
+        if (!product)
+            goto noproduct;
+
+        cur = strchr(product, '/');
+        if (!cur)
+            goto noproduct;
+
+        usb_vendor = strtoul(cur + 1, &next, 16);
+        if (!next || next == cur + 1 || usb_vendor > 0xffff)
+            goto noproduct;
+
+        cur = next;
+        usb_model = strtoul(cur + 1, &next, 16);
+        if (!next || next == cur + 1 || usb_model > 0xffff)
+            goto noproduct;
+
+        attrs.usb_id = Xprintf("%04x:%04x", usb_vendor, usb_model);
+        if (attrs.usb_id)
+            LOG_PROPERTY(path, "PRODUCT", product);
     }
+
+noproduct:
+
     if (!name)
         name = "(unnamed)";
     else
@@ -152,12 +179,6 @@ device_added(struct udev_device *udev_device)
         } else if (!strcmp(key, "ID_VENDOR")) {
             LOG_PROPERTY(path, key, value);
             attrs.vendor = value;
-        } else if (!strcmp(key, "ID_VENDOR_ID")) {
-            LOG_PROPERTY(path, key, value);
-            usb_vendor = value;
-        } else if (!strcmp(key, "ID_VENDOR_MODEL")) {
-            LOG_PROPERTY(path, key, value);
-            usb_model = value;
         } else if (!strcmp(key, "ID_INPUT_KEY")) {
             LOG_PROPERTY(path, key, value);
             attrs.flags |= ATTR_KEYBOARD;
@@ -179,16 +200,6 @@ device_added(struct udev_device *udev_device)
         }
     }
 
-    /* construct USB ID in lowercase hex - "0000:ffff" */
-    if (usb_vendor && usb_model) {
-        attrs.usb_id = Xprintf("%s:%s", usb_vendor, usb_model);
-        if (attrs.usb_id) {
-            char *cur;
-            for (cur = attrs.usb_id; *cur; cur++)
-                *cur = tolower(*cur);
-        }
-    }
-
     LogMessage(X_INFO, "config/udev: Adding input device %s (%s)\n",
                name, path);
     rc = NewInputDeviceRequest(options, &attrs, &dev);
-- 
1.7.1