Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0bb85751 authored by Sven Eckelmann's avatar Sven Eckelmann
Browse files

batman-adv: Check type of x and y in seq_(before|after) 



seq_before and seq_after depend on the fact that both sequence numbers
have the same type and thus the same bitwidth. We can ensure that by
compile time checking using a compare between the pointer to the
temporary buffers which were created using the typeof of both
parameters. For example gcc would create a warning like
"warning: comparison of distinct pointer types lacks a cast".

Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
parent f5d33d37

net/batman-adv/main.h

+5 −2
Original line number Diff line number Diff line
@@ -194,7 +194,10 @@ static inline int compare_eth(const void *data1, const void *data2) 
 *  - before adding more than 127 to the starting value - it is a predecessor,

 *  - when adding 128 - it is neither a predecessor nor a successor,

 *  - after adding more than 127 to the starting value - it is a successor */

#define seq_before(x, y) ({typeof(x) _dummy = (x - y); \

#define seq_before(x, y) ({typeof(x) _d1 = (x); \

			  typeof(y) _d2 = (y); \

			  typeof(x) _dummy = (_d1 - _d2); \

			  (void) (&_d1 == &_d2); \

			  _dummy > smallest_signed_int(_dummy); })

#define seq_after(x, y) seq_before(y, x)