+void sockaddrcpy(sockaddr_t *a, const sockaddr_t *b) {
+ if(b->sa.sa_family != AF_UNKNOWN) {
+ *a = *b;
+ } else {
+ a->unknown.family = AF_UNKNOWN;
+ a->unknown.address = xstrdup(b->unknown.address);
+ a->unknown.port = xstrdup(b->unknown.port);
+ }
+}
+
+void sockaddrfree(sockaddr_t *a) {
+ if(a->sa.sa_family == AF_UNKNOWN) {
+ free(a->unknown.address);
+ free(a->unknown.port);
+ }
+}
+
+void sockaddrunmap(sockaddr_t *sa) {
+ if(sa->sa.sa_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&sa->in6.sin6_addr)) {
+ sa->in.sin_addr.s_addr = ((uint32_t *) & sa->in6.sin6_addr)[3];
+ sa->in.sin_family = AF_INET;
+ }
+}
+
+/* Subnet mask handling */
+
+int maskcmp(const void *va, const void *vb, int masklen) {
+ int i, m, result;
+ const char *a = va;
+ const char *b = vb;
+
+ for(m = masklen, i = 0; m >= 8; m -= 8, i++) {
+ result = a[i] - b[i];
+ if(result)
+ return result;
+ }