plugins/pppoatm: Restructure code to avoid possibility of integer ove…

…rflow This avoids the theoretical possibility of integer overflow in adding a constant before dividing in order to get the effect of rounding up. Instead we divide and add 1 if the original value modulo the divisor is non-zero. Signed-off-by: Paul Mackerras <[email protected]>
ppp-project · Aug 20, 2024 · 17f3240 · 17f3240
1 parent 7eb932b
commit 17f3240
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/pppd/plugins/pppoatm/text2qos.c b/pppd/plugins/pppoatm/text2qos.c
@@ -66,8 +66,9 @@ int __t2q_get_rate(const char **text,int up)
     }
     else if (!strncmp(end,"cps",3)) end += 3;
 	else if (!strncmp(end,"bps",3)) {
-		rate = (rate+(up ? 8*ATM_CELL_PAYLOAD-1 : 0))/8/
-		  ATM_CELL_PAYLOAD;
+		if (up && rate % (8 * ATM_CELL_PAYLOAD) == 0)
+			up = 0;
+		rate = rate / (8 * ATM_CELL_PAYLOAD) + !!up;
 		end += 3;
 	    }
 	    else if (multiplier) return RATE_ERROR;