dccp ccid-3: X truncated due to type conversion
This fixes a bug in computing the inter-packet-interval t_ipi = s/X: scaled_div32(a, b) uses u32 for b, but in "scaled_div32(s, X)" the type of the sending rate `X' is u64. Since X is scaled by 2^6, this truncates rates greater than 2^26 Bps (~537 Mbps). Using full 64-bit division now. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
This commit is contained in:
parent
1e8a287c79
commit
7deb0f8510
|
@ -15,7 +15,7 @@
|
|||
* (at your option) any later version.
|
||||
*/
|
||||
#include <linux/types.h>
|
||||
#include <asm/div64.h>
|
||||
#include <linux/math64.h>
|
||||
#include "../../dccp.h"
|
||||
/* internal includes that this module exports: */
|
||||
#include "loss_interval.h"
|
||||
|
@ -29,21 +29,19 @@ extern int tfrc_debug;
|
|||
#endif
|
||||
|
||||
/* integer-arithmetic divisions of type (a * 1000000)/b */
|
||||
static inline u64 scaled_div(u64 a, u32 b)
|
||||
static inline u64 scaled_div(u64 a, u64 b)
|
||||
{
|
||||
BUG_ON(b==0);
|
||||
a *= 1000000;
|
||||
do_div(a, b);
|
||||
return a;
|
||||
return div64_u64(a * 1000000, b);
|
||||
}
|
||||
|
||||
static inline u32 scaled_div32(u64 a, u32 b)
|
||||
static inline u32 scaled_div32(u64 a, u64 b)
|
||||
{
|
||||
u64 result = scaled_div(a, b);
|
||||
|
||||
if (result > UINT_MAX) {
|
||||
DCCP_CRIT("Overflow: a(%llu)/b(%u) > ~0U",
|
||||
(unsigned long long)a, b);
|
||||
DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX",
|
||||
(unsigned long long)a, (unsigned long long)b);
|
||||
return UINT_MAX;
|
||||
}
|
||||
return result;
|
||||
|
|
Loading…
Reference in a new issue