PERFORCE change 149768 for review

[Hans Petter Selasky]

http://perforce.freebsd.org/chv.cgi?CH=149768

Change 149768 by hselasky at hselasky_laptop001 on 2008/09/14 18:02:52

	
	Cleanup USB permissions code. Use "vaccess" instead of re-inventing the wheel.

Affected files ...

.. //depot/projects/usb/src/sys/dev/usb2/core/usb2_core.h#20 edit
.. //depot/projects/usb/src/sys/dev/usb2/core/usb2_dev.c#32 edit

Differences ...

==== //depot/projects/usb/src/sys/dev/usb2/core/usb2_core.h#20 (text+ko) ====

@@ -42,14 +42,6 @@
 #define	USB_USE_CONDVAR 0
 #endif
 
-#ifndef USB_TD_GET_RUID
-#define	USB_TD_GET_RUID(td) (td)->td_ucred->cr_ruid
-#endif
-
-#ifndef USB_TD_GET_RGID
-#define	USB_TD_GET_RGID(td) (td)->td_ucred->cr_rgid
-#endif
-
 #ifndef USB_TD_GET_PROC
 #define	USB_TD_GET_PROC(td) (td)->td_proc
 #endif

==== //depot/projects/usb/src/sys/dev/usb2/core/usb2_dev.c#32 (text+ko) ====

@@ -74,7 +74,7 @@
 
 static uint32_t usb2_path_convert_one(const char **pp);
 static uint32_t usb2_path_convert(const char *path);
-static uint8_t usb2_match_perm(struct usb2_perm *psystem, struct usb2_perm *puser);
+static int usb2_check_access(int fflags, struct usb2_perm *puser);
 static int usb2_fifo_open(struct usb2_fifo *f, struct file *fp, struct thread *td, int fflags);
 static void usb2_fifo_close(struct usb2_fifo *f, struct thread *td, int fflags);
 static void usb2_dev_init(void *arg);
@@ -421,37 +421,33 @@
 }
 
 /*------------------------------------------------------------------------*
- *	usb2_match_perm
+ *	usb2_check_access
  *
- * This function will compare two permission structures and see if
- * they are matching.
+ * This function will verify the given access information.
  *
  * Return values:
- * 0: Permissions are not matching.
- * Else: Permissions are matching.
+ * 0: Access granted.
+ * Else: No access granted.
  *------------------------------------------------------------------------*/
-static uint8_t
-usb2_match_perm(struct usb2_perm *psystem, struct usb2_perm *puser)
+static int
+usb2_check_access(int fflags, struct usb2_perm *puser)
 {
-	uint16_t mode;
+	mode_t accmode;
 
-	if ((psystem->mode != 0) && (puser->mode != 0)) {
+	if ((fflags & (FWRITE | FREAD)) && (puser->mode != 0)) {
 		/* continue */
 	} else {
-		return (0);		/* no access */
+		return (EPERM);		/* no access */
 	}
 
-	/* get the mode differences with regard to the bits that are set */
-	mode = ((psystem->mode ^ puser->mode) & puser->mode);
+	accmode = 0;
+	if (fflags & FWRITE)
+		accmode |= VWRITE;
+	if (fflags & FREAD)
+		accmode |= VREAD;
 
-	if ((psystem->uid == puser->uid) && ((mode & 0700) == 0)) {
-		return (1);		/* allow access */
-	} else if ((psystem->gid == puser->gid) && ((mode & 0070) == 0)) {
-		return (1);		/* allow access */
-	} else if ((mode & 0007) == 0) {
-		return (1);		/* allow access */
-	}
-	return (0);			/* deny access */
+	return (vaccess(VCHR, puser->mode, puser->uid,
+	    puser->gid, accmode, curthread->td_ucred, NULL));
 }
 
 /*------------------------------------------------------------------------*
@@ -1117,7 +1113,6 @@
 usb2_check_thread_perm(struct usb2_device *udev, struct thread *td,
     int fflags, uint8_t iface_index, uint8_t ep_index)
 {
-	struct usb2_perm perm;
 	struct usb2_interface *iface;
 	int err;
 
@@ -1128,30 +1123,20 @@
 	if (iface->idesc == NULL) {
 		return (EINVAL);
 	}
-	/* set default value */
-	bzero(&perm, sizeof(perm));
-
-	/* create a permissions mask */
-	perm.uid = USB_TD_GET_RUID(td);
-	perm.uid = USB_TD_GET_RGID(td);
-	perm.mode = 0;
-	if (fflags & FREAD)
-		perm.mode |= 0444;
-	if (fflags & FWRITE)
-		perm.mode |= 0222;
-
 	/* scan down the permissions tree */
 	if ((ep_index != 0) && iface &&
-	    usb2_match_perm(&perm, &iface->perm)) {
+	    (usb2_check_access(fflags, &iface->perm) == 0)) {
 		/* we got access through the interface */
 		err = 0;
-	} else if (udev && usb2_match_perm(&perm, &udev->perm)) {
+	} else if (udev &&
+	    (usb2_check_access(fflags, &udev->perm) == 0)) {
 		/* we got access through the device */
 		err = 0;
-	} else if (udev->bus && usb2_match_perm(&perm, &udev->bus->perm)) {
+	} else if (udev->bus &&
+	    (usb2_check_access(fflags, &udev->bus->perm) == 0)) {
 		/* we got access through the USB bus */
 		err = 0;
-	} else if (usb2_match_perm(&perm, &usb2_perm)) {
+	} else if (usb2_check_access(fflags, &usb2_perm) == 0) {
 		/* we got general access */
 		err = 0;
 	} else {
@@ -1409,9 +1394,14 @@
 	 * Create a dummy device so that we are visible. This device
 	 * should never be opened. Therefore a space character is
 	 * appended after the USB device name.
+	 *
+	 * NOTE: The permissions of this device is 0777, because we
+	 * check the permissions again in the open routine against the
+	 * real USB permissions which are not 0777. Else USB access
+	 * will be limited to one user and one group.
 	 */
 	usb2_dev = make_dev(&usb2_devsw, 0, UID_ROOT, GID_OPERATOR,
-	    0000, USB_DEVICE_NAME " ");
+	    0777, USB_DEVICE_NAME " ");
 	if (usb2_dev == NULL) {
 		DPRINTFN(0, "Could not create usb bus device!\n");
 	}