map: fix psidlen becoming negative (FS#1430)

[openwrt/openwrt.git] / package / network / ipv6 / map / src / mapcalc.c

diff --git a/package/network/ipv6/map/src/mapcalc.c b/package/network/ipv6/map/src/mapcalc.c
index 6233bce731b784459e41f6abcb183f893acb41b7..66610c4279dd86da28625260deb39f7ec921c3ed 100644 (file)
--- a/package/network/ipv6/map/src/mapcalc.c
+++ b/package/network/ipv6/map/src/mapcalc.c
@@ -4,6 +4,7 @@
  * Author: Steven Barth <cyrus@openwrt.org>
  * Copyright (c) 2014-2015 cisco Systems, Inc.
  * Copyright (c) 2015 Steven Barth <cyrus@openwrt.org>
+ * Copyright (c) 2018 Hans Dedecker <dedeckeh@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2
@@ -311,25 +312,30 @@ int main(int argc, char *argv[])
 
                if (psidlen <= 0) {
                        psidlen = ealen - (32 - prefix4len);
+                       if (psidlen < 0)
+                               psidlen = 0;
+
                        psid = -1;
                }
 
-               if (psid < 0 && psidlen <= 16 && psidlen >= 0 && pdlen >= 0 && ealen >= psidlen) {
+               if (prefix4len < 0 || prefix6len < 0 || ealen < 0 || psidlen > 16 || ealen < psidlen) {
+                       fprintf(stderr, "Skipping invalid or incomplete rule: %s\n", argv[i]);
+                       status = 1;
+                       continue;
+               }
+
+               if (psid < 0 && psidlen >= 0 && pdlen >= 0) {
                        bmemcpys64(&psid16, &pd, prefix6len + ealen - psidlen, psidlen);
                        psid = be16_to_cpu(psid16);
                }
 
-               psid = psid >> (16 - psidlen);
-               psid16 = cpu_to_be16(psid);
-               psid = psid << (16 - psidlen);
-
-               if (prefix4len < 0 || prefix6len < 0 || ealen < 0 || ealen < psidlen) {
-                       fprintf(stderr, "Skipping invalid or incomplete rule: %s\n", argv[i]);
-                       status = 1;
-                       continue;
+               if (psidlen > 0) {
+                       psid = psid >> (16 - psidlen);
+                       psid16 = cpu_to_be16(psid);
+                       psid = psid << (16 - psidlen);
                }
 
-               if ((pdlen >= 0 || ealen == psidlen) && ealen >= psidlen) {
+               if (pdlen >= 0 || ealen == psidlen) {
                        bmemcpys64(&ipv4addr, &pd, prefix6len, ealen - psidlen);
                        ipv4addr.s_addr = htonl(ntohl(ipv4addr.s_addr) >> prefix4len);
                        bmemcpy(&ipv4addr, &ipv4prefix, prefix4len);