ippool: Add IPv6 support to IP pool implementation
Extend the IP pool implementation to be able to manage both pools
of 32bit addresses (IPv4) as well as pools of 128bit addresses (IPv6)
Change-Id: Ib98cc4bf634d6be9a7bf8c03a24e629455fcafc8
diff --git a/lib/in46_addr.c b/lib/in46_addr.c
new file mode 100644
index 0000000..903ceec
--- /dev/null
+++ b/lib/in46_addr.c
@@ -0,0 +1,148 @@
+/*
+ * IPv4/v6 address functions.
+ * Copyright (C) 2017 by Harald Welte <laforge@gnumonks.org>
+ *
+ * The contents of this file may be used under the terms of the GNU
+ * General Public License Version 2, provided that the above copyright
+ * notice and this permission notice is included in all copies or
+ * substantial portions of the software.
+ *
+ */
+
+#include "../lib/in46_addr.h"
+
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*! Return the address family of given \reff in46_addr argument */
+int in46a_to_af(const struct in46_addr *in)
+{
+ switch (in->len) {
+ case 4:
+ return AF_INET;
+ case 16:
+ return AF_INET6;
+ default:
+ return -1;
+ }
+}
+
+/*! Convert \ref in46_addr to sockaddr_storage */
+int in46a_to_sas(struct sockaddr_storage *out, const struct in46_addr *in)
+{
+ struct sockaddr_in *sin = (struct sockaddr_in *)out;
+ struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)out;
+
+ switch (in->len) {
+ case 4:
+ sin->sin_family = AF_INET;
+ sin->sin_addr = in->v4;
+ break;
+ case 16:
+ sin6->sin6_family = AF_INET;
+ sin6->sin6_addr = in->v6;
+ break;
+ default:
+ return -1;
+ }
+
+ return 0;
+}
+
+/*! Convenience wrapper around inet_ntop() for \ref in46_addr */
+const char *in46a_ntop(const struct in46_addr *in, char *dst, socklen_t dst_size)
+{
+ int af = in46a_to_af(in);
+ if (af < 0)
+ return NULL;
+
+ return inet_ntop(af, (const void *) &in->v4, dst, dst_size);
+}
+
+/*! Determine if two in46_addr are equal or not
+ * \returns 1 in case they are equal; 0 otherwise */
+int in46a_equal(const struct in46_addr *a, const struct in46_addr *b)
+{
+ if (a->len == b->len && !memcmp(&a->v6, &b->v6, a->len))
+ return 1;
+ else
+ return 0;
+}
+
+/*! Match if IPv6 addr1 + addr2 are within same \a mask */
+static int ipv6_within_mask(const struct in6_addr *addr1, const struct in6_addr *addr2,
+ const struct in6_addr *mask)
+{
+ struct in6_addr masked = *addr2;
+#if defined(__linux__)
+ masked.s6_addr32[0] &= mask->s6_addr32[0];
+ masked.s6_addr32[1] &= mask->s6_addr32[1];
+ masked.s6_addr32[2] &= mask->s6_addr32[2];
+ masked.s6_addr32[3] &= mask->s6_addr32[3];
+#else
+ masked.__u6_addr.__u6_addr32[0] &= mask->__u6_addr.__u6_addr32[0];
+ masked.__u6_addr.__u6_addr32[1] &= mask->__u6_addr.__u6_addr32[1];
+ masked.__u6_addr.__u6_addr32[2] &= mask->__u6_addr.__u6_addr32[2];
+ masked.__u6_addr.__u6_addr32[3] &= mask->__u6_addr.__u6_addr32[3];
+#endif
+ if (!memcmp(addr1, &masked, sizeof(struct in6_addr)))
+ return 1;
+ else
+ return 0;
+}
+
+/*! Create an IPv6 netmask from the given prefix length */
+static void create_ipv6_netmask(struct in6_addr *netmask, int prefixlen)
+{
+ uint32_t *p_netmask;
+ memset(netmask, 0, sizeof(struct in6_addr));
+ if (prefixlen < 0)
+ prefixlen = 0;
+ else if (128 < prefixlen)
+ prefixlen = 128;
+
+#if defined(__linux__)
+ p_netmask = &netmask->s6_addr32[0];
+#else
+ p_netmask = &netmask->__u6_addr.__u6_addr32[0];
+#endif
+ while (32 < prefixlen) {
+ *p_netmask = 0xffffffff;
+ p_netmask++;
+ prefixlen -= 32;
+ }
+ if (prefixlen != 0) {
+ *p_netmask = htonl(0xFFFFFFFF << (32 - prefixlen));
+ }
+}
+
+/*! Determine if given \a addr is within given \a net + \a prefixlen
+ * Builds the netmask from \a net + \a prefixlen and matches it to \a addr
+ * \returns 1 in case of a match, 0 otherwise */
+int in46a_within_mask(const struct in46_addr *addr, const struct in46_addr *net, size_t prefixlen)
+{
+ struct in_addr netmask;
+ struct in6_addr netmask6;
+
+ if (addr->len != net->len)
+ return 0;
+
+ switch (addr->len) {
+ case 4:
+ netmask.s_addr = htonl(0xFFFFFFFF << (32 - prefixlen));
+ if ((addr->v4.s_addr & netmask.s_addr) == net->v4.s_addr)
+ return 1;
+ else
+ return 0;
+ case 16:
+ create_ipv6_netmask(&netmask6, prefixlen);
+ return ipv6_within_mask(&addr->v6, &net->v6, &netmask6);
+ default:
+ return 0;
+ }
+}