1 files changed, 115 insertions, 0 deletions
diff --git a/scramble_wlw.c b/scramble_wlw.c
new file mode 100644
index 0000000..ac52718
--- /dev/null
+++ b/scramble_wlw.c
@@ -0,0 +1,115 @@
+#include "scramble_wlw.h"
+#include "patricia.h"
+#include <arpa/inet.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define PREFIX_DELIMITER ",; "
+
+static patricia_tree_t *tree4 = NULL;
+static patricia_tree_t *tree6 = NULL;
+static prefix_t lookup_pfix4;
+static prefix_t lookup_pfix6;
+static scrambler_ip4_t _scrambler_ip4 = NULL;
+static scrambler_ip6_t _scrambler_ip6 = NULL;
+
+
+static inline int
+scramble_wlw_lookup_addr4(const struct in_addr *sin) {
+    if (tree4 == NULL)
+        return 0;
+    memcpy(&lookup_pfix4.add.sin, sin, sizeof(*sin));
+    return (patricia_search_best2(tree4, &lookup_pfix4, 1) != NULL);
+}
+
+static inline int
+scramble_wlw_lookup_addr6(const struct in6_addr *sin6) {
+    if (tree6 == NULL)
+        return 0;
+    memcpy(&lookup_pfix6.add.sin6, sin6, sizeof(*sin6));
+    return (patricia_search_best2(tree6, &lookup_pfix6, 1) != NULL);
+}
+
+/* Init white list wrapper.  Can be called again to add wl-state.
+ * prefix_wlist is a list of ip4 and ip6 prefixes, separated by
+ * one of the PREFIX_DELIMITER
+ * s4 is an ipv4 address scrambler
+ * s6 is an ipv6 address scrambler
+ */
+void
+scramble_wlw_init(const char *prefix_wlist, scrambler_ip4_t s4, scrambler_ip6_t s6) {
+    char *plist = strdup(prefix_wlist), *cp;
+    int afam, bits;
+    patricia_tree_t **tree;
+
+    _scrambler_ip4 = s4;
+    _scrambler_ip6 = s6;
+
+    for (cp = strtok(plist, PREFIX_DELIMITER); cp != NULL; cp = strtok(NULL, PREFIX_DELIMITER)) {
+        if (index(cp, ':') == NULL) {
+            tree = &tree4;
+            afam = AF_INET;
+            bits = 32;
+        } else {
+            tree = &tree6;
+            afam = AF_INET6;
+            bits = 128;
+        }
+        prefix_t *pref = ascii2prefix(afam, cp);
+        if (pref == NULL) {
+            fprintf(stderr, "ERROR: can't parse prefix %s\n", cp);
+            exit(1);
+        }
+        if (index(cp, '/') == NULL) {
+            pref->bitlen = bits;
+        }
+        if (*tree == NULL) {
+            *tree = New_Patricia(bits);
+        }
+        patricia_lookup(*tree, pref);
+        Deref_Prefix(pref);
+    }
+    lookup_pfix4.family = AF_INET;
+    lookup_pfix4.bitlen = 32;
+    lookup_pfix4.ref_count = 0;
+
+    lookup_pfix6.family = AF_INET6;
+    lookup_pfix6.bitlen = 128;
+    lookup_pfix6.ref_count = 0;
+}
+
+/* Clear state */
+void
+scramble_wlw_clear() {
+    if (tree4) {
+        Destroy_Patricia(tree4, NULL);
+        tree4 = NULL;
+    }
+    if (tree6) {
+        Destroy_Patricia(tree6, NULL);
+        tree6 = NULL;
+    }
+}
+
+
+uint32_t
+scramble_wlw_v4(uint32_t oldsrc, int pass_bits) {
+    struct in_addr sin;
+    if (tree4) {
+        sin.s_addr = oldsrc;
+        if (scramble_wlw_lookup_addr4(&sin))
+            return oldsrc; /* whitelisted */
+    }
+    return _scrambler_ip4(oldsrc, pass_bits);
+}
+
+void
+scramble_wlw_v6(struct in6_addr *sin6, int pass_bits) {
+    if (tree6) {
+        if (scramble_wlw_lookup_addr6(sin6))
+            return; /* whitelisted */
+    }
+    _scrambler_ip6(sin6, pass_bits);
+}
+