Date: Sat, 10 Jan 2009 19:44:01 GMT From: Hans Petter Selasky <hselasky@FreeBSD.org> To: Perforce Change Reviews <perforce@FreeBSD.org> Subject: PERFORCE change 155932 for review Message-ID: <200901101944.n0AJi1Tc025398@repoman.freebsd.org>
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http://perforce.freebsd.org/chv.cgi?CH=155932 Change 155932 by hselasky@hselasky_laptop001 on 2009/01/10 19:43:54 Refactor "usb2_desc_foreach()" to not use "USB_ADD_BYTES" macro. Requested by Dag-Erling Smørgrav. More functions will be refactored to not use the "USB_ADD_BYTES" macro when I find time. Affected files ... .. //depot/projects/usb/src/sys/dev/usb2/core/usb2_parse.c#6 edit Differences ... ==== //depot/projects/usb/src/sys/dev/usb2/core/usb2_parse.c#6 (text+ko) ==== @@ -43,25 +43,44 @@ * Else: Next descriptor after "desc" *------------------------------------------------------------------------*/ struct usb2_descriptor * -usb2_desc_foreach(struct usb2_config_descriptor *cd, struct usb2_descriptor *desc) +usb2_desc_foreach(struct usb2_config_descriptor *cd, + struct usb2_descriptor *_desc) { - void *end; + uint8_t *desc_next; + uint8_t *start; + uint8_t *end; + uint8_t *desc; - if (cd == NULL) { + /* be NULL safe */ + if (cd == NULL) return (NULL); - } - end = USB_ADD_BYTES(cd, UGETW(cd->wTotalLength)); + + /* We assume that the "wTotalLength" has been checked. */ + start = (uint8_t *)cd; + end = start + UGETW(cd->wTotalLength); + desc = (uint8_t *)_desc; + + /* Get start of next USB descriptor. */ + if (desc == NULL) + desc = start; + else + desc = desc + desc[0]; + + /* Check that the next USB descriptor is within the range. */ + if ((desc < start) || (desc >= end)) + return (NULL); /* out of range, or EOD */ + + /* Check that the second next USB descriptor is within range. */ + desc_next = desc + desc[0]; + if ((desc_next < start) || (desc_next > end)) + return (NULL); /* out of range */ + + /* Check minimum descriptor length. */ + if (desc[0] < 3) + return (NULL); /* too short descriptor */ - if (desc == NULL) { - desc = USB_ADD_BYTES(cd, 0); - } else { - desc = USB_ADD_BYTES(desc, desc->bLength); - } - return (((((void *)desc) >= ((void *)cd)) && - (((void *)desc) < end) && - (USB_ADD_BYTES(desc, desc->bLength) >= ((void *)cd)) && - (USB_ADD_BYTES(desc, desc->bLength) <= end) && - (desc->bLength >= sizeof(*desc))) ? desc : NULL); + /* Return start of next descriptor. */ + return ((struct usb2_descriptor *)desc); } /*------------------------------------------------------------------------* @@ -140,7 +159,6 @@ desc = ((void *)d); while ((desc = usb2_desc_foreach(cd, desc))) { - if (desc->bDescriptorType == UDESC_INTERFACE) { break; } @@ -195,7 +213,6 @@ uint16_t n = 0; while ((desc = usb2_desc_foreach(cd, desc))) { - if ((desc->bDescriptorType == UDESC_INTERFACE) && (desc->bLength >= sizeof(*id))) { id = (void *)desc;
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