- Move OFW_NAME_MAX, used as a limit for OFW property names and device

  identifiers, to openfirmio.h as OFIOCMAXNAME, so programs can use it
  for buffer sizes etc.
  Note: Although this is only a rough upper limit to make the code more
  robust and to prevent the allocation of ridiculous amounts of memory,
  the current limit of one page (8191 + '\0' in openfirm_getstr()) still
  appears a bit high. The maximum length of OFW property names is 31.
  I didn't find a maximum length for the device identifiers in the OFW
  documentation but it certainly is much smaller than 8191, too.
- Enable the OFIOCSET ioctl, i.e. move it out from under #if 0.
- Don't use openfirm_getstr() for the property value in OFIOCSET, there
  are also properties whose values aren't strings and it makes sense to
  use a different maximum length for property values than OFW_NAME_MAX/
  OFIOCMAXNAME. The maximum accepted property value is defined in
  openfirmio.h as OFIOCMAXVALUE (currently the maximum size of the value
  of the nvramrc property).
- Make OFIOCSET not return EINVAL when OF_setprop() returns a different
  length for the written value than it was told to write, this is normal
  for the text string values of the properties in the OFW /options node.
  Instead, only return EINVAL if OF_setprop() returned -1 (value could
  not be written or property could not be created). Add a comment about
  the specialty of the OFW /options node.
- Make OFIOCSET return the length of the written value returned by
  OF_setprop(), just like OF_getprop() does. Quite useful, at least for
  debugging.

Reviewed by:	tmm

2 files changed, 24 insertions, 13 deletions

diff --git a/sys/dev/ofw/openfirmio.c b/sys/dev/ofw/openfirmio.c
index 358109e..adb3929 100644
--- a/sys/dev/ofw/openfirmio.c
+++ b/sys/dev/ofw/openfirmio.c
@@ -74,9 +74,6 @@ static phandle_t lastnode;	/* speed hack */
 static int openfirm_checkid(phandle_t, phandle_t);
 static int openfirm_getstr(int, const char *, char **);
 
-/* Maximum accepted name length. */
-#define	OFW_NAME_MAX	8191
-
 /*
  * Verify target ID is valid (exists in the OPENPROM tree), as
  * listed from node ID sid forward.
@@ -99,7 +96,7 @@ openfirm_getstr(int len, const char *user, char **cpp)
 	char *cp;
 
 	/* Reject obvious bogus requests */
-	if ((u_int)len > OFW_NAME_MAX)
+	if ((u_int)len > OFIOCMAXNAME)
 		return (ENAMETOOLONG);
 
 	*cpp = cp = malloc(len + 1, M_TEMP, M_WAITOK);
@@ -129,9 +126,7 @@ openfirm_ioctl(dev_t dev, u_long cmd, caddr_t data, int flags,
 		*(phandle_t *) data = OF_finddevice("/options");
 		return (0);
 	case OFIOCGET:
-#if 0
 	case OFIOCSET:
-#endif
 	case OFIOCNEXTPROP:
 	case OFIOCFINDDEVICE:
 	case OFIOCGETPROPLEN:
@@ -186,23 +181,36 @@ openfirm_ioctl(dev_t dev, u_long cmd, caddr_t data, int flags,
 		error = copyout(value, of->of_buf, len);
 		break;
 
-#if 0
 	case OFIOCSET:
+		/*
+		 * Note: Text string values for at least the /options node
+		 * have to be null-terminated and the length paramter must
+		 * include this terminating null. However, like OF_getprop(),
+		 * OF_setprop() will return the the actual length of the text
+		 * string, i.e. omitting the terminating null.
+		 */
 		if ((flags & FWRITE) == 0)
 			return (EBADF);
 		if (node == 0)
 			return (EINVAL);
+		if ((u_int)of->of_buflen > OFIOCMAXVALUE)
+			return (ENAMETOOLONG);
 		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
 		if (error)
 			break;
-		error = openfirm_getstr(of->of_buflen, of->of_buf, &value);
+		value = malloc(of->of_buflen, M_TEMP, M_WAITOK);
+		if (value == NULL) {
+			error = ENOMEM;
+			break;
+		}
+		error = copyin(of->of_buf, value, of->of_buflen);
 		if (error)
 			break;
 		len = OF_setprop(node, name, value, of->of_buflen);
-		if (len != of->of_buflen)
+		if (len < 0)
 			error = EINVAL;
+		of->of_buflen = len;
 		break;
-#endif
 
 	case OFIOCNEXTPROP:
 		if (node == 0 || of->of_buflen < 0)
diff --git a/sys/dev/ofw/openfirmio.h b/sys/dev/ofw/openfirmio.h
index ae5837e..c4f21d2 100644
--- a/sys/dev/ofw/openfirmio.h
+++ b/sys/dev/ofw/openfirmio.h
@@ -54,10 +54,8 @@ struct ofiocdesc {
 
 /* Get openprom field. */
 #define	OFIOCGET	_IOWR(OFIOC_BASE, 1, struct ofiocdesc)
-#if 0
 /* Set openprom field. */
-#define	OFIOCSET	_IOW(OFIOC_BASE, 2, struct ofiocdesc)
-#endif
+#define	OFIOCSET	_IOWR(OFIOC_BASE, 2, struct ofiocdesc)
 /* Get next property. */
 #define	OFIOCNEXTPROP	_IOWR(OFIOC_BASE, 3, struct ofiocdesc)
 /* Get options node. */
@@ -71,4 +69,9 @@ struct ofiocdesc {
 /* Retrieve the size of a property. */
 #define	OFIOCGETPROPLEN	_IOWR(OFIOC_BASE, 8, struct ofiocdesc)
 
+/* Maximum accepted name length. */
+#define	OFIOCMAXNAME	8191
+/* Maximum accepted value length (maximum of nvramrc property). */
+#define	OFIOCMAXVALUE	8192
+
 #endif /* _DEV_OFW_OPENFIRMIO_H_ */