map: fix psidlen becoming negative (FS#1430)

Fix psidlen becomes negative in case embedded address bit lenght is smaller than
IPv4 suffix length.
While at it improve parameter checking making the code more logical and
easier to read.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

diff --git a/package/network/ipv6/map/Makefile b/package/network/ipv6/map/Makefile
index ce04235f28a823519c8f0340d0ccf399cb18166e..77967042b381af66b51de6a3eb7c27c246aa1554 100644 (file)
--- a/package/network/ipv6/map/Makefile
+++ b/package/network/ipv6/map/Makefile
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=map
 PKG_VERSION:=4
-PKG_RELEASE:=9
+PKG_RELEASE:=10
 PKG_LICENSE:=GPL-2.0
 
 include $(INCLUDE_DIR)/package.mk

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);