tail overflow in function xbee_cbuf_put

[yuanye0814]

When length equals end_space, the tail value may overflow. cbuf->tail = cbuf->tail + length;

such as, when cbuf->maks = 255; cbuf->tail = 255; length = 1;

after calculation: cbuf->tail = 256.

[tomlogic]

Ah, good catch! Looks like it should be if (length >= end_space). We need to get a test in test/xbee/t_cbuf.c to trigger that.

[tomlogic]

Thanks for reporting this, @yuanye0814.

[acpie360]

Instead of using memcpy for the put operation, would that be easier to simply call xbee_cbuf_putch()? `unsigned int xbee_cbuf_put(xbee_cbuf_t FAR cbuf, const void FAR buffer, unsigned int length) { int res; int i; const uint8_t * data;

data = buffer;

for (i = 0; i < length; i++)
{
    res = xbee_cbuf_putch(cbuf, data[i]);
    if (res == 0)
    {
        break;
    }
}

return i;

}`

[tomlogic]

Although easier and would have avoided this bug, it would be far less efficient to call xbee_cbuf_putch() for each character.