usb/80773: "usbd_get_string()" could have taken a length parameter

[M. Warner Losh]

Please find enclosed a patch for this.  I'm sitting on the fence as to
whether or not to commit it, since it is an api/abi change.

Warner
-------------- next part --------------
Index: if_cdce.c
===================================================================
RCS file: /home/ncvs/src/sys/dev/usb/if_cdce.c,v
retrieving revision 1.24
diff -u -r1.24 if_cdce.c
--- if_cdce.c	23 Jun 2007 06:47:43 -0000	1.24
+++ if_cdce.c	30 Jun 2007 14:28:41 -0000
@@ -280,7 +280,8 @@
 
 	ue = (const usb_cdc_ethernet_descriptor_t *)usb_find_desc(dev,
 	    UDESC_INTERFACE, UDESCSUB_CDC_ENF);
-	if (!ue || usbd_get_string(dev, ue->iMacAddress, eaddr_str)) {
+	if (!ue || usbd_get_string(dev, ue->iMacAddress, eaddr_str,
+	    sizeof(eaddr_str))) {
 		/* Fake MAC address */
 		device_printf(sc->cdce_dev, "faking MAC address\n");
 		eaddr[0]= 0x2a;
Index: uhub.c
===================================================================
RCS file: /home/ncvs/src/sys/dev/usb/uhub.c,v
retrieving revision 1.81
diff -u -r1.81 uhub.c
--- uhub.c	29 Jun 2007 20:34:42 -0000	1.81
+++ uhub.c	30 Jun 2007 14:28:41 -0000
@@ -655,7 +655,8 @@
 
 found_dev:
 	/* XXX can sleep */
-	(void)usbd_get_string(dev, dev->ddesc.iSerialNumber, &serial[0]);
+	(void)usbd_get_string(dev, dev->ddesc.iSerialNumber, serial,
+	    sizeof(serial));
 	if (dev->ifacenums == NULL) {
 		snprintf(buf, buflen, "vendor=0x%04x product=0x%04x "
 		    "devclass=0x%02x devsubclass=0x%02x "
Index: usb_subr.c
===================================================================
RCS file: /home/ncvs/src/sys/dev/usb/usb_subr.c,v
retrieving revision 1.94
diff -u -r1.94 usb_subr.c
--- usb_subr.c	20 Jun 2007 05:10:54 -0000	1.94
+++ usb_subr.c	30 Jun 2007 14:28:42 -0000
@@ -213,12 +213,14 @@
 	}
 
 	if (usedev) {
-		if (usbd_get_string(dev, udd->iManufacturer, v))
+		if (usbd_get_string(dev, udd->iManufacturer, v,
+		    USB_MAX_STRING_LEN))
 			vendor = NULL;
 		else
 			vendor = v;
 		usbd_trim_spaces(vendor);
-		if (usbd_get_string(dev, udd->iProduct, p))
+		if (usbd_get_string(dev, udd->iProduct, p,
+		    USB_MAX_STRING_LEN))
 			product = NULL;
 		else
 			product = p;
Index: usbdi.c
===================================================================
RCS file: /home/ncvs/src/sys/dev/usb/usbdi.c,v
retrieving revision 1.102
diff -u -r1.102 usbdi.c
--- usbdi.c	20 Jun 2007 05:10:54 -0000	1.102
+++ usbdi.c	30 Jun 2007 14:28:42 -0000
@@ -1310,7 +1310,7 @@
 }
 
 usbd_status
-usbd_get_string(usbd_device_handle dev, int si, char *buf)
+usbd_get_string(usbd_device_handle dev, int si, char *buf, size_t len)
 {
 	int swap = dev->quirks->uq_flags & UQ_SWAP_UNICODE;
 	usb_string_descriptor_t us;
@@ -1321,6 +1321,8 @@
 	int size;
 
 	buf[0] = '\0';
+	if (len == 0)
+		return (USBD_NORMAL_COMPLETION);
 	if (si == 0)
 		return (USBD_INVAL);
 	if (dev->quirks->uq_flags & UQ_NO_STRINGS)
@@ -1342,7 +1344,7 @@
 		return (err);
 	s = buf;
 	n = size / 2 - 1;
-	for (i = 0; i < n; i++) {
+	for (i = 0; i < n && i < len - 1; i++) {
 		c = UGETW(us.bString[i]);
 		/* Convert from Unicode, handle buggy strings. */
 		if ((c & 0xff00) == 0)
Index: usbdi.h
===================================================================
RCS file: /home/ncvs/src/sys/dev/usb/usbdi.h,v
retrieving revision 1.62
diff -u -r1.62 usbdi.h
--- usbdi.h	12 Jun 2007 19:40:20 -0000	1.62
+++ usbdi.h	30 Jun 2007 14:28:42 -0000
@@ -173,7 +173,8 @@
 
 int usbd_ratecheck(struct timeval *last);
 
-usbd_status usbd_get_string(usbd_device_handle dev, int si, char *buf);
+usbd_status usbd_get_string(usbd_device_handle dev, int si, char *buf,
+    size_t len);
 
 /* An iterator for descriptors. */
 typedef struct {