+
+ return 1;
+}
+
+int in_addr_null(unsigned family, union in_addr_union *u) {
+ assert(u);
+
+ if (family == AF_INET)
+ return u->in.s_addr == 0;
+
+ if (family == AF_INET6)
+ return
+ u->in6.s6_addr32[0] == 0 &&
+ u->in6.s6_addr32[1] == 0 &&
+ u->in6.s6_addr32[2] == 0 &&
+ u->in6.s6_addr32[3] == 0;
+
+ return -EAFNOSUPPORT;
+}
+
+
+int in_addr_equal(unsigned family, union in_addr_union *a, union in_addr_union *b) {
+ assert(a);
+ assert(b);
+
+ if (family == AF_INET)
+ return a->in.s_addr == b->in.s_addr;
+
+ if (family == AF_INET6)
+ return
+ a->in6.s6_addr32[0] == b->in6.s6_addr32[0] &&
+ a->in6.s6_addr32[1] == b->in6.s6_addr32[1] &&
+ a->in6.s6_addr32[2] == b->in6.s6_addr32[2] &&
+ a->in6.s6_addr32[3] == b->in6.s6_addr32[3];
+
+ return -EAFNOSUPPORT;
+}
+
+int in_addr_prefix_intersect(
+ unsigned family,
+ const union in_addr_union *a,
+ unsigned aprefixlen,
+ const union in_addr_union *b,
+ unsigned bprefixlen) {
+
+ unsigned m;
+
+ assert(a);
+ assert(b);
+
+ /* Checks whether there are any addresses that are in both
+ * networks */
+
+ m = MIN(aprefixlen, bprefixlen);
+
+ if (family == AF_INET) {
+ uint32_t x, nm;
+
+ x = be32toh(a->in.s_addr ^ b->in.s_addr);
+ nm = (m == 0) ? 0 : 0xFFFFFFFFUL << (32 - m);
+
+ return (x & nm) == 0;
+ }
+
+ if (family == AF_INET6) {
+ unsigned i;
+
+ if (m > 128)
+ m = 128;
+
+ for (i = 0; i < 16; i++) {
+ uint8_t x, nm;
+
+ x = a->in6.s6_addr[i] ^ b->in6.s6_addr[i];
+
+ if (m < 8)
+ nm = 0xFF << (8 - m);
+ else
+ nm = 0xFF;
+
+ if ((x & nm) != 0)
+ return 0;
+
+ if (m > 8)
+ m -= 8;
+ else
+ m = 0;
+ }
+
+ return 1;
+ }
+
+ return -EAFNOSUPPORT;
+}
+
+int in_addr_prefix_next(unsigned family, union in_addr_union *u, unsigned prefixlen) {
+ assert(u);
+
+ /* Increases the network part of an address by one. Returns
+ * positive it that succeeds, or 0 if this overflows. */
+
+ if (prefixlen <= 0)
+ return 0;
+
+ if (family == AF_INET) {
+ uint32_t c, n;
+
+ if (prefixlen > 32)
+ prefixlen = 32;
+
+ c = be32toh(u->in.s_addr);
+ n = c + (1UL << (32 - prefixlen));
+ if (n < c)
+ return 0;
+ n &= 0xFFFFFFFFUL << (32 - prefixlen);
+
+ u->in.s_addr = htobe32(n);
+ return 1;