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Diffstat (limited to 'net/netfilter/ipset/pfxlen.c')
-rw-r--r--net/netfilter/ipset/pfxlen.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/net/netfilter/ipset/pfxlen.c b/net/netfilter/ipset/pfxlen.c
index 23f8c8162214..bd13d66220f1 100644
--- a/net/netfilter/ipset/pfxlen.c
+++ b/net/netfilter/ipset/pfxlen.c
@@ -148,7 +148,7 @@ const union nf_inet_addr ip_set_netmask_map[] = {
EXPORT_SYMBOL_GPL(ip_set_netmask_map);
#undef E
-#define E(a, b, c, d) \
+#define E(a, b, c, d) \
{.ip6 = { (__force __be32) a, (__force __be32) b, \
(__force __be32) c, (__force __be32) d, \
} }
@@ -289,3 +289,24 @@ const union nf_inet_addr ip_set_hostmask_map[] = {
E(0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF),
};
EXPORT_SYMBOL_GPL(ip_set_hostmask_map);
+
+/* Find the largest network which matches the range from left, in host order. */
+u32
+ip_set_range_to_cidr(u32 from, u32 to, u8 *cidr)
+{
+ u32 last;
+ u8 i;
+
+ for (i = 1; i < 32; i++) {
+ if ((from & ip_set_hostmask(i)) != from)
+ continue;
+ last = from | ~ip_set_hostmask(i);
+ if (!after(last, to)) {
+ *cidr = i;
+ return last;
+ }
+ }
+ *cidr = 32;
+ return from;
+}
+EXPORT_SYMBOL_GPL(ip_set_range_to_cidr);