libxtables: add xtables_ip[6]mask_to_cidr
This patch adds generic functions to return the mask in CIDR
notation whenever is possible.
This patch also simplifies xtables_ip[6]mask_to_numeric, that
now use these new two functions.
This patch also bumps libxtables_vcurrent and libxtables_vage
since we added a couple new interfaces (thanks to Jan Engelhardt
for his little reminder on this).
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/libxtables/xtables.c b/libxtables/xtables.c
index 014e115..d818579 100644
--- a/libxtables/xtables.c
+++ b/libxtables/xtables.c
@@ -1133,28 +1133,43 @@
return xtables_ipaddr_to_numeric(addr);
}
-const char *xtables_ipmask_to_numeric(const struct in_addr *mask)
+int xtables_ipmask_to_cidr(const struct in_addr *mask)
{
- static char buf[20];
uint32_t maskaddr, bits;
int i;
maskaddr = ntohl(mask->s_addr);
-
+ /* shortcut for /32 networks */
if (maskaddr == 0xFFFFFFFFL)
- /* we don't want to see "/32" */
- return "";
+ return 32;
i = 32;
bits = 0xFFFFFFFEL;
while (--i >= 0 && maskaddr != bits)
bits <<= 1;
if (i >= 0)
- sprintf(buf, "/%d", i);
- else
+ return i;
+
+ /* this mask cannot be converted to CIDR notation */
+ return -1;
+}
+
+const char *xtables_ipmask_to_numeric(const struct in_addr *mask)
+{
+ static char buf[20];
+ uint32_t cidr;
+
+ cidr = xtables_ipmask_to_cidr(mask);
+ if (cidr < 0) {
/* mask was not a decent combination of 1's and 0's */
sprintf(buf, "/%s", xtables_ipaddr_to_numeric(mask));
+ return buf;
+ } else if (cidr == 32) {
+ /* we don't want to see "/32" */
+ return "";
+ }
+ sprintf(buf, "/%d", cidr);
return buf;
}
@@ -1465,7 +1480,7 @@
return xtables_ip6addr_to_numeric(addr);
}
-static int ip6addr_prefix_length(const struct in6_addr *k)
+int xtables_ip6mask_to_cidr(const struct in6_addr *k)
{
unsigned int bits = 0;
uint32_t a, b, c, d;
@@ -1492,7 +1507,7 @@
const char *xtables_ip6mask_to_numeric(const struct in6_addr *addrp)
{
static char buf[50+2];
- int l = ip6addr_prefix_length(addrp);
+ int l = xtables_ip6mask_to_cidr(addrp);
if (l == -1) {
strcpy(buf, "/");