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

[M. Warner Losh]

The following reply was made to PR usb/80773; it has been noted by GNATS.

From: "M. Warner Losh" <imp at bsdimp.com>
To: linimon at freebsd.org
Cc: hselasky at c2i.net, freebsd-usb at freebsd.org, bug-followup at freebsd.org
Subject: Re: usb/80773: "usbd_get_string()" could have taken a length
 parameter
Date: Sat, 30 Jun 2007 09:08:18 -0600 (MDT)

 ----Next_Part(Sat_Jun_30_09_08_18_2007_041)--
 Content-Type: Text/Plain; charset=us-ascii
 Content-Transfer-Encoding: 7bit
 
 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(Sat_Jun_30_09_08_18_2007_041)--
 Content-Type: Text/Plain; charset=us-ascii
 Content-Transfer-Encoding: 7bit
 Content-Disposition: inline; filename=patch
 
 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 {
 
 ----Next_Part(Sat_Jun_30_09_08_18_2007_041)----