Make sure the prefixlength of subnets is sane.

[oweals/tinc.git] / src / subnet.c

diff --git a/src/subnet.c b/src/subnet.c
index b52dfa53b3a37d6f068e1a57e9f47e7b3dc15331..52ed443713e2147779061bb135b98f3ba28c7eb9 100644 (file)
--- a/src/subnet.c
+++ b/src/subnet.c
@@ -1,7 +1,7 @@
 /*
     subnet.c -- handle subnet lookups and lists
-    Copyright (C) 2000-2004 Guus Sliepen <guus@tinc-vpn.org>,
-                  2000-2004 Ivo Timmermans <ivo@tinc-vpn.org>
+    Copyright (C) 2000-2006 Guus Sliepen <guus@tinc-vpn.org>,
+                  2000-2005 Ivo Timmermans
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -188,11 +188,17 @@ bool str2net(subnet_t *subnet, const char *subnetstr)
 
        if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d",
                          &x[0], &x[1], &x[2], &x[3], &l) == 5) {
+               if(l < 0 || l > 32)
+                       return false;
+
                subnet->type = SUBNET_IPV4;
                subnet->net.ipv4.prefixlength = l;
 
-               for(i = 0; i < 4; i++)
+               for(i = 0; i < 4; i++) {
+                       if(x[i] > 255)
+                               return false;
                        subnet->net.ipv4.address.x[i] = x[i];
+               }
 
                return true;
        }
@@ -200,6 +206,9 @@ bool str2net(subnet_t *subnet, const char *subnetstr)
        if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d",
                          &x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
                          &l) == 9) {
+               if(l < 0 || l > 128)
+                       return false;
+
                subnet->type = SUBNET_IPV6;
                subnet->net.ipv6.prefixlength = l;
 
@@ -213,8 +222,11 @@ bool str2net(subnet_t *subnet, const char *subnetstr)
                subnet->type = SUBNET_IPV4;
                subnet->net.ipv4.prefixlength = 32;
 
-               for(i = 0; i < 4; i++)
+               for(i = 0; i < 4; i++) {
+                       if(x[i] > 255)
+                               return false;
                        subnet->net.ipv4.address.x[i] = x[i];
+               }
 
                return true;
        }
@@ -247,6 +259,11 @@ bool net2str(char *netstr, int len, const subnet_t *subnet)
 {
        cp();
 
+       if(!netstr || !subnet) {
+               logger(LOG_ERR, _("net2str() was called with netstr=%p, subnet=%p!\n"), netstr, subnet);
+               return false;
+       }
+
        switch (subnet->type) {
                case SUBNET_MAC:
                        snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx",
@@ -337,12 +354,14 @@ subnet_t *lookup_subnet_ipv4(const ipv4_t *address)
                                break;
                        }
 
-                       if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength, sizeof(ipv4_t)))
+                       if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength))
                                break;
                        else {
                                /* Otherwise, see if there is a bigger enclosing subnet */
 
                                subnet.net.ipv4.prefixlength = p->net.ipv4.prefixlength - 1;
+                               if(subnet.net.ipv4.prefixlength < 0 || subnet.net.ipv4.prefixlength > 32)
+                                       return NULL;
                                maskcpy(&subnet.net.ipv4.address, &p->net.ipv4.address, subnet.net.ipv4.prefixlength, sizeof(ipv4_t));
                        }
                }
@@ -373,12 +392,14 @@ subnet_t *lookup_subnet_ipv6(const ipv6_t *address)
                        if(p->type != SUBNET_IPV6)
                                return NULL;
 
-                       if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength, sizeof(ipv6_t)))
+                       if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength))
                                break;
                        else {
                                /* Otherwise, see if there is a bigger enclosing subnet */
 
                                subnet.net.ipv6.prefixlength = p->net.ipv6.prefixlength - 1;
+                               if(subnet.net.ipv6.prefixlength < 0 || subnet.net.ipv6.prefixlength > 128)
+                                       return NULL;
                                maskcpy(&subnet.net.ipv6.address, &p->net.ipv6.address, subnet.net.ipv6.prefixlength, sizeof(ipv6_t));
                        }
                }
@@ -424,9 +445,6 @@ void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
                        execute_script(name, envp);
        }
 
-       net2str(netstr, sizeof netstr, subnet);
-       envp[6] = envp[7] = NULL;
-
        for(i = 0; i < (owner != myself ? 6 : 4); i++)
                free(envp[i]);