MFp4 //depot/projects/usb@158868

Fix bugs and improve HID parsing.
- fix possible memory leak found
- fix possible NULL pointer access
- fix possible invalid memory read
- parsing improvements
- reset item data position when a new report ID is detected.

Submitted by:	Hans Petter Selasky
This commit is contained in:
Andrew Thompson 2009-03-08 22:58:19 +00:00
parent 4309a3fb19
commit da6c1373fa
2 changed files with 203 additions and 123 deletions

View File

@ -57,19 +57,25 @@ __FBSDID("$FreeBSD$");
#include <dev/usb/usb_hid.h>
static void hid_clear_local(struct hid_item *);
static uint8_t hid_get_byte(struct hid_data *s, const uint16_t wSize);
#define MAXUSAGE 100
#define MAXUSAGE 64
#define MAXPUSH 4
struct hid_data {
const uint8_t *start;
const uint8_t *end;
const uint8_t *p;
struct hid_item cur;
int32_t usages[MAXUSAGE];
int nu;
int minset;
int multi;
int multimax;
struct hid_item cur[MAXPUSH];
int32_t usages_min[MAXUSAGE];
int32_t usages_max[MAXUSAGE];
int kindset;
uint8_t pushlevel; /* current pushlevel */
uint8_t ncount; /* end usage item count */
uint8_t icount; /* current usage item count */
uint8_t nusage; /* end "usages_min/max" index */
uint8_t iusage; /* current "usages_min/max" index */
uint8_t ousage; /* current "usages_min/max" offset */
uint8_t susage; /* usage set flags */
};
/*------------------------------------------------------------------------*
@ -79,6 +85,8 @@ static void
hid_clear_local(struct hid_item *c)
{
c->loc.count = 0;
c->loc.size = 0;
c->usage = 0;
c->usage_minimum = 0;
c->usage_maximum = 0;
@ -99,6 +107,12 @@ hid_start_parse(const void *d, int len, int kindset)
{
struct hid_data *s;
if ((kindset-1) & kindset) {
DPRINTFN(0, "Only one bit can be "
"set in the kindset\n");
return (NULL);
}
s = malloc(sizeof *s, M_TEMP, M_WAITOK | M_ZERO);
s->start = s->p = d;
s->end = ((const uint8_t *)d) + len;
@ -112,60 +126,103 @@ hid_start_parse(const void *d, int len, int kindset)
void
hid_end_parse(struct hid_data *s)
{
if (s == NULL)
return;
while (s->cur.next != NULL) {
struct hid_item *hi = s->cur.next->next;
free(s->cur.next, M_TEMP);
s->cur.next = hi;
}
free(s, M_TEMP);
}
/*------------------------------------------------------------------------*
* get byte from HID descriptor
*------------------------------------------------------------------------*/
static uint8_t
hid_get_byte(struct hid_data *s, const uint16_t wSize)
{
const uint8_t *ptr;
uint8_t retval;
ptr = s->p;
/* check if end is reached */
if (ptr == s->end)
return (0);
/* read out a byte */
retval = *ptr;
/* check if data pointer can be advanced by "wSize" bytes */
if ((s->end - ptr) < wSize)
ptr = s->end;
else
ptr += wSize;
/* update pointer */
s->p = ptr;
return (retval);
}
/*------------------------------------------------------------------------*
* hid_get_item
*------------------------------------------------------------------------*/
int
hid_get_item(struct hid_data *s, struct hid_item *h)
{
struct hid_item *c = &s->cur;
struct hid_item *c;
unsigned int bTag, bType, bSize;
uint32_t oldpos;
const uint8_t *data;
int32_t mask;
int32_t dval;
const uint8_t *p;
struct hid_item *hi;
int i;
top:
if (s->multimax != 0) {
if (s->multi < s->multimax) {
c->usage = s->usages[MIN(s->multi, s->nu - 1)];
s->multi++;
*h = *c;
c->loc.pos += c->loc.size;
h->next = 0;
return (1);
if (s == NULL)
return (0);
c = &s->cur[s->pushlevel];
top:
/* check if there is an array of items */
if ((s->icount != s->ncount) &&
(s->iusage != s->nusage)) {
dval = s->usages_min[s->iusage] + s->ousage;
c->usage = dval;
if (dval == s->usages_max[s->iusage]) {
s->iusage ++;
s->ousage = 0;
} else {
c->loc.count = s->multimax;
s->multimax = 0;
s->nu = 0;
hid_clear_local(c);
s->ousage ++;
}
s->icount ++;
/*
* Only copy HID item, increment position and return
* if correct kindset!
*/
if (s->kindset & (1 << c->kind)) {
*h = *c;
DPRINTFN(1, "%u,%u,%u\n", h->loc.pos,
h->loc.size, h->loc.count);
c->loc.pos += c->loc.size * c->loc.count;
return (1);
}
}
for (;;) {
p = s->p;
if ((p >= s->end) || (p < s->start))
return (0);
bSize = *p++;
/* reset state variables */
s->icount = 0;
s->ncount = 0;
s->iusage = 0;
s->nusage = 0;
s->susage = 0;
s->ousage = 0;
hid_clear_local(c);
/* get next item */
while (s->p != s->end) {
bSize = hid_get_byte(s, 1);
if (bSize == 0xfe) {
/* long item */
bSize = *p++;
bSize |= *p++ << 8;
bTag = *p++;
data = p;
p += bSize;
bSize = hid_get_byte(s, 1);
bSize |= hid_get_byte(s, 1) << 8;
bTag = hid_get_byte(s, 1);
bType = 0xff; /* XXX what should it be */
} else {
/* short item */
@ -174,30 +231,33 @@ hid_get_item(struct hid_data *s, struct hid_item *h)
bSize &= 3;
if (bSize == 3)
bSize = 4;
data = p;
p += bSize;
}
s->p = p;
switch (bSize) {
case 0:
dval = 0;
mask = 0;
break;
case 1:
dval = (int8_t)*data++;
dval = (int8_t)hid_get_byte(s, 1);
mask = 0xFF;
break;
case 2:
dval = *data++;
dval |= *data++ << 8;
dval = hid_get_byte(s, 1);
dval |= hid_get_byte(s, 1) << 8;
dval = (int16_t)dval;
mask = 0xFFFF;
break;
case 4:
dval = *data++;
dval |= *data++ << 8;
dval |= *data++ << 16;
dval |= *data++ << 24;
dval = hid_get_byte(s, 1);
dval |= hid_get_byte(s, 1) << 8;
dval |= hid_get_byte(s, 1) << 16;
dval |= hid_get_byte(s, 1) << 24;
mask = 0xFFFFFFFF;
break;
default:
printf("BAD LENGTH %d\n", bSize);
dval = hid_get_byte(s, bSize);
DPRINTFN(0, "bad length %u (data=0x%02x)\n",
bSize, dval);
continue;
}
@ -205,44 +265,35 @@ hid_get_item(struct hid_data *s, struct hid_item *h)
case 0: /* Main */
switch (bTag) {
case 8: /* Input */
if (!(s->kindset & (1 << hid_input))) {
if (s->nu > 0)
s->nu--;
continue;
}
c->kind = hid_input;
c->flags = dval;
ret:
if (c->flags & HIO_VARIABLE) {
s->multimax = c->loc.count;
s->multi = 0;
/* range check usage count */
if (c->loc.count > 255) {
DPRINTFN(0, "Number of "
"items truncated to 255\n");
s->ncount = 255;
} else
s->ncount = c->loc.count;
/*
* The "top" loop will return
* one and one item:
*/
c->loc.count = 1;
if (s->minset) {
for (i = c->usage_minimum;
i <= c->usage_maximum;
i++) {
s->usages[s->nu] = i;
if (s->nu < MAXUSAGE - 1)
s->nu++;
}
s->minset = 0;
}
goto top;
} else {
*h = *c;
h->next = 0;
c->loc.pos +=
c->loc.size * c->loc.count;
hid_clear_local(c);
s->minset = 0;
return (1);
/* make sure we have a usage */
if (s->nusage == 0) {
s->usages_min[s->nusage] = 0;
s->usages_max[s->nusage] = 0;
s->nusage = 1;
}
s->ncount = 1;
}
goto top;
case 9: /* Output */
if (!(s->kindset & (1 << hid_output))) {
if (s->nu > 0)
s->nu--;
continue;
}
c->kind = hid_output;
c->flags = dval;
goto ret;
@ -251,27 +302,22 @@ hid_get_item(struct hid_data *s, struct hid_item *h)
c->collection = dval;
c->collevel++;
*h = *c;
hid_clear_local(c);
s->nu = 0;
return (1);
case 11: /* Feature */
if (!(s->kindset & (1 << hid_feature))) {
if (s->nu > 0)
s->nu--;
continue;
}
c->kind = hid_feature;
c->flags = dval;
goto ret;
case 12: /* End collection */
c->kind = hid_endcollection;
if (c->collevel == 0) {
DPRINTFN(0, "invalid end collection\n");
return (0);
}
c->collevel--;
*h = *c;
hid_clear_local(c);
s->nu = 0;
return (1);
default:
printf("Main bTag=%d\n", bTag);
DPRINTFN(0, "Main bTag=%d\n", bTag);
break;
}
break;
@ -303,53 +349,88 @@ hid_get_item(struct hid_data *s, struct hid_item *h)
break;
case 8:
c->report_ID = dval;
/* new report - reset position */
c->loc.pos = 0;
break;
case 9:
c->loc.count = dval;
break;
case 10: /* Push */
hi = malloc(sizeof *hi, M_TEMP, M_WAITOK);
*hi = s->cur;
c->next = hi;
s->pushlevel ++;
if (s->pushlevel < MAXPUSH) {
s->cur[s->pushlevel] = *c;
c = &s->cur[s->pushlevel];
} else {
DPRINTFN(0, "Cannot push "
"item @ %d!\n", s->pushlevel);
}
break;
case 11: /* Pop */
hi = c->next;
oldpos = c->loc.pos;
s->cur = *hi;
c->loc.pos = oldpos;
free(hi, M_TEMP);
s->pushlevel --;
if (s->pushlevel < MAXPUSH) {
/* preserve position */
oldpos = c->loc.pos;
c = &s->cur[s->pushlevel];
c->loc.pos = oldpos;
} else {
DPRINTFN(0, "Cannot pop "
"item @ %d!\n", s->pushlevel);
}
break;
default:
printf("Global bTag=%d\n", bTag);
DPRINTFN(0, "Global bTag=%d\n", bTag);
break;
}
break;
case 2: /* Local */
switch (bTag) {
case 0:
if (bSize == 1)
dval = c->_usage_page | (dval & 0xff);
else if (bSize == 2)
dval = c->_usage_page | (dval & 0xffff);
c->usage = dval;
if (s->nu < MAXUSAGE)
s->usages[s->nu++] = dval;
/* else XXX */
if (bSize != 4)
dval = (dval & mask) | c->_usage_page;
if (s->nusage < MAXUSAGE) {
s->usages_min[s->nusage] = dval;
s->usages_max[s->nusage] = dval;
s->nusage ++;
} else {
DPRINTFN(0, "max usage reached!\n");
}
/* clear any pending usage sets */
s->susage = 0;
break;
case 1:
s->minset = 1;
if (bSize == 1)
dval = c->_usage_page | (dval & 0xff);
else if (bSize == 2)
dval = c->_usage_page | (dval & 0xffff);
s->susage |= 1;
if (bSize != 4)
dval = (dval & mask) | c->_usage_page;
c->usage_minimum = dval;
break;
goto check_set;
case 2:
if (bSize == 1)
dval = c->_usage_page | (dval & 0xff);
else if (bSize == 2)
dval = c->_usage_page | (dval & 0xffff);
s->susage |= 2;
if (bSize != 4)
dval = (dval & mask) | c->_usage_page;
c->usage_maximum = dval;
check_set:
if (s->susage != 3)
break;
/* sanity check */
if ((s->nusage < MAXUSAGE) &&
(c->usage_minimum < c->usage_maximum)) {
/* add usage range */
s->usages_min[s->nusage] =
c->usage_minimum;
s->usages_max[s->nusage] =
c->usage_maximum;
s->nusage ++;
} else {
DPRINTFN(0, "Usage set dropped!\n");
}
s->susage = 0;
break;
case 3:
c->designator_index = dval;
@ -373,15 +454,16 @@ hid_get_item(struct hid_data *s, struct hid_item *h)
c->set_delimiter = dval;
break;
default:
printf("Local bTag=%d\n", bTag);
DPRINTFN(0, "Local bTag=%d\n", bTag);
break;
}
break;
default:
printf("default bType=%d\n", bType);
DPRINTFN(0, "default bType=%d\n", bType);
break;
}
}
return (0);
}
/*------------------------------------------------------------------------*

View File

@ -70,8 +70,6 @@ struct hid_item {
uint32_t flags;
/* Location */
struct hid_location loc;
/* */
struct hid_item *next;
};
/* prototypes from "usb2_hid.c" */