From 0a3c8cefd4a154948799baaaa246cf0eba050eff Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Fri, 1 Jun 2001 08:02:09 +0000 Subject: [PATCH] Fix subnet_lookup() for overlapping subnets. Needs rethinking. --- src/subnet.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-) diff --git a/src/subnet.c b/src/subnet.c index a08e2de7..51b1cd7a 100644 --- a/src/subnet.c +++ b/src/subnet.c @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: subnet.c,v 1.1.2.18 2001/01/07 20:19:08 guus Exp $ + $Id: subnet.c,v 1.1.2.19 2001/06/01 08:02:09 guus Exp $ */ #include "config.h" @@ -57,16 +57,12 @@ cp int subnet_compare_ipv4(subnet_t *a, subnet_t *b) { cp - /* If the subnet of a falls within the range of subnet b, - then we consider a smaller then b. - Otherwise, the addresses alone (and not the subnet masks) will be compared. - */ + /* We compare as if a subnet is a number that equals (address << 32 + netmask). */ - if(a->net.ipv4.mask > b->net.ipv4.mask) - if((a->net.ipv4.address & b->net.ipv4.mask) == b->net.ipv4.address) - return -1; - - return a->net.ipv4.address - b->net.ipv4.address; + if(a->net.ipv4.address == b->net.ipv4.address) + return a->net.ipv4.mask - b->net.ipv4.mask; + else + return a->net.ipv4.address - b->net.ipv4.address; } int subnet_compare_ipv6(subnet_t *a, subnet_t *b) @@ -276,14 +272,29 @@ cp subnet.net.ipv4.address = *address; subnet.net.ipv4.mask = 0xFFFFFFFF; - p = (subnet_t *)avl_search_closest_greater(subnet_tree, &subnet); + do + { + /* Go find subnet */ + + p = (subnet_t *)avl_search_closest_smaller(subnet_tree, &subnet); /* Check if the found subnet REALLY matches */ cp - if(p && ((*address & p->net.ipv4.mask) == p->net.ipv4.address)) - return p; - else - return NULL; + if(p) + { + if ((*address & p->net.ipv4.mask) == p->net.ipv4.address) + break; + else + { + /* Otherwise, see if there is a bigger enclosing subnet */ + + subnet.net.ipv4.mask = p->net.ipv4.mask << 1; + subnet.net.ipv4.address &= subnet.net.ipv4.mask; + } + } + } while (p); + + return p; } subnet_t *lookup_subnet_ipv6(ipv6_t *address) -- 2.20.1