endpoint: simplify creation logic

5 files changed, 61 insertions, 48 deletions

diff --git a/bus.h b/bus.h
index 07ec0c3a5e4..60d9edd801e 100644
--- a/bus.h
+++ b/bus.h
@@ -18,7 +18,7 @@
 #include "internal.h"
 
 /**
- * kdbus_bus - bus instance
+ * kdbus_bus - bus in a namespace
  * @kref		reference count
  * @disconnected	invalidated data
  * @uid_owner		the uid of the owner of the bus
diff --git a/endpoint.c b/endpoint.c
index 9d758e15d76..cc7dc99a9ac 100644
--- a/endpoint.c
+++ b/endpoint.c
@@ -216,11 +216,13 @@ int kdbus_ep_remove(struct kdbus_ep *ep)
 	return 0;
 }
 
-int kdbus_ep_kmake_user(void __user *buf, struct kdbus_cmd_ep_kmake **kmake)
+int kdbus_ep_make_user(void __user *buf,
+		       struct kdbus_cmd_ep_make **make, char **name)
 {
 	u64 size;
-	struct kdbus_cmd_ep_kmake *km;
+	struct kdbus_cmd_ep_make *m;
 	const struct kdbus_item *item;
+	const char *n = NULL;
 	int ret;
 
 	if (kdbus_size_get_user(&size, buf, struct kdbus_cmd_ep_make))
@@ -229,25 +231,21 @@ int kdbus_ep_kmake_user(void __user *buf, struct kdbus_cmd_ep_kmake **kmake)
 	if (size < sizeof(struct kdbus_cmd_ep_make) || size > KDBUS_MAKE_MAX_SIZE)
 		return -EMSGSIZE;
 
-	km = kmalloc(sizeof(struct kdbus_cmd_ep_kmake) + size, GFP_KERNEL);
-	if (!km)
-		return -ENOMEM;
-
-	memset(km, 0, offsetof(struct kdbus_cmd_ep_kmake, make));
-	if (copy_from_user(&km->make, buf, size)) {
-		ret = -EFAULT;
+	m = memdup_user(buf, size);
+	if (IS_ERR(m)) {
+		ret = PTR_ERR(m);
 		goto exit;
 	}
 
-	KDBUS_PART_FOREACH(item, &km->make, items) {
-		if (!KDBUS_PART_VALID(item, &km->make)) {
+	KDBUS_PART_FOREACH(item, m, items) {
+		if (!KDBUS_PART_VALID(item, m)) {
 			ret = -EINVAL;
 			goto exit;
 		}
 
 		switch (item->type) {
 		case KDBUS_MAKE_NAME:
-			if (km->name) {
+			if (n) {
 				ret = -EEXIST;
 				goto exit;
 			}
@@ -268,7 +266,7 @@ int kdbus_ep_kmake_user(void __user *buf, struct kdbus_cmd_ep_kmake **kmake)
 				goto exit;
 			}
 
-			km->name = item->str;
+			n = item->str;
 			continue;
 
 		default:
@@ -277,18 +275,19 @@ int kdbus_ep_kmake_user(void __user *buf, struct kdbus_cmd_ep_kmake **kmake)
 		}
 	}
 
-	if (!KDBUS_PART_END(item, &km->make))
+	if (!KDBUS_PART_END(item, m))
 		return -EINVAL;
 
-	if (!km->name) {
+	if (!n) {
 		ret = -EBADMSG;
 		goto exit;
 	}
 
-	*kmake = km;
+	*make = m;
+	*name = (char *)n;
 	return 0;
 
 exit:
-	kfree(km);
+	kfree(m);
 	return ret;
 }
diff --git a/endpoint.h b/endpoint.h
index 5b52fc66c8d..1937a4e94b7 100644
--- a/endpoint.h
+++ b/endpoint.h
@@ -15,33 +15,45 @@
 #include "internal.h"
 
 /*
- * kdbus endpoint
- * - offers access to a bus, the default device node name is "bus"
- * - additional endpoints can carry a specific policy/filters
+ * kdbus endpoint - enpoint to access a bus
+ * @kref		reference count
+ * @disconnected	invalidated data
+ * @bus			bus behind this endpoint
+ * @name		name of the endpoint
+ * @id			id of this endpoint on the bus
+ * @minor		minor of this endpoint in the namespace major
+ * @dev			device node of this endpoint
+ * @mode		file mode of this endpoint device node
+ * @uid			uid owning this endpoint
+ * @gid			gid owning this endpoint
+ * @bus_entry		bus' endpoints
+ * @wait		wake up this endpoint
+ * @lock		endpoint data lock
+ * @policy_db		uploaded policy
+ * @policy_open		default endpoint policy
+ *
+ * An enpoint offers access to a bus; the default device node name is "bus".
+ * Additional custom endpoints to the same bus can be created and they can
+ * carry their own policies/filters.
  */
 struct kdbus_ep {
-	struct kref kref;		/* reference count */
-	bool disconnected;		/* invalidated data */
-	struct kdbus_bus *bus;		/* bus behind this endpoint */
-	const char *name;		/* name, prefixed with uid */
-	u64 id;				/* id of this endpoint on the bus */
-	unsigned int minor;		/* minor of this endpoint in the namespace major */
-	struct device *dev;		/* device node of this endpoint */
-	umode_t mode;			/* file mode of this endpoint device node */
-	kuid_t uid;			/* uid owning this endpoint */
-	kgid_t gid;			/* gid owning this endpoint */
-	struct list_head bus_entry;	/* bus' endpoints */
-	wait_queue_head_t wait;		/* wake up this endpoint */
+	struct kref kref;
+	bool disconnected;
+	struct kdbus_bus *bus;
+	const char *name;
+	u64 id;
+	unsigned int minor;
+	struct device *dev;
+	umode_t mode;
+	kuid_t uid;
+	kgid_t gid;
+	struct list_head bus_entry;
+	wait_queue_head_t wait;
 	struct mutex lock;
 	struct kdbus_policy_db *policy_db;
 	bool policy_open:1;
 };
 
-struct kdbus_cmd_ep_kmake {
-	const char *name;
-	struct kdbus_cmd_ep_make make;
-};
-
 struct kdbus_ep *kdbus_ep_ref(struct kdbus_ep *ep);
 void kdbus_ep_unref(struct kdbus_ep *ep);
 
@@ -49,5 +61,6 @@ int kdbus_ep_new(struct kdbus_bus *bus, const char *name,
 		 umode_t mode, kuid_t uid, kgid_t gid, bool policy);
 int kdbus_ep_remove(struct kdbus_ep *ep);
 void kdbus_ep_disconnect(struct kdbus_ep *ep);
-int kdbus_ep_kmake_user(void __user *buf, struct kdbus_cmd_ep_kmake **kmake);
+int kdbus_ep_make_user(void __user *buf,
+		       struct kdbus_cmd_ep_make **make, char **name);
 #endif
diff --git a/handle.c b/handle.c
index 846b7358237..5597e5a58ef 100644
--- a/handle.c
+++ b/handle.c
@@ -277,7 +277,7 @@ static long kdbus_handle_ioctl_ep(struct file *file, unsigned int cmd,
 				  void __user *buf)
 {
 	struct kdbus_handle *handle = file->private_data;
-	struct kdbus_cmd_ep_kmake *kmake = NULL;
+	struct kdbus_cmd_ep_make *m = NULL;
 	struct kdbus_cmd_hello *hello = NULL;
 	long ret = 0;
 
@@ -285,31 +285,32 @@ static long kdbus_handle_ioctl_ep(struct file *file, unsigned int cmd,
 	case KDBUS_CMD_EP_MAKE: {
 		umode_t mode = 0;
 		kgid_t gid = KGIDT_INIT(0);
+		char *n;
 
 		if (!KDBUS_IS_ALIGNED8((uintptr_t)buf)) {
 			ret = -EFAULT;
 			break;
 		}
 
-		ret = kdbus_ep_kmake_user(buf, &kmake);
+		ret = kdbus_ep_make_user(buf, &m, &n);
 		if (ret < 0)
 			break;
 
-		if (!kdbus_check_flags(kmake->make.flags)) {
+		if (!kdbus_check_flags(m->flags)) {
 			ret = -ENOTSUPP;
 			break;
 		}
 
-		if (kmake->make.flags & KDBUS_MAKE_ACCESS_WORLD) {
+		if (m->flags & KDBUS_MAKE_ACCESS_WORLD) {
 			mode = 0666;
-		} else if (kmake->make.flags & KDBUS_MAKE_ACCESS_GROUP) {
+		} else if (m->flags & KDBUS_MAKE_ACCESS_GROUP) {
 			mode = 0660;
 			gid = current_fsgid();
 		}
 
-		ret = kdbus_ep_new(handle->ep->bus, kmake->name, mode,
+		ret = kdbus_ep_new(handle->ep->bus, n, mode,
 				   current_fsuid(), gid,
-				   kmake->make.flags & KDBUS_MAKE_POLICY_OPEN);
+				   m->flags & KDBUS_MAKE_POLICY_OPEN);
 
 		handle->type = KDBUS_HANDLE_EP_OWNER;
 		break;
@@ -373,7 +374,7 @@ static long kdbus_handle_ioctl_ep(struct file *file, unsigned int cmd,
 		break;
 	}
 
-	kfree(kmake);
+	kfree(m);
 	kfree(hello);
 
 	return ret;
diff --git a/kdbus.txt b/kdbus.txt
index f12261d85ea..a07ec38627b 100644
--- a/kdbus.txt
+++ b/kdbus.txt
@@ -450,7 +450,7 @@ ECOMM
   A peer does not accept the file descriptors addressed to it.
 
 EDESTADDRREQ
-  The well-known bus name is missing, to address the destination.
+  The well-known bus name is required but missing.
 
 EDOM
   The size of data does not match the expectations. Used for the