1 files changed, 74 insertions, 0 deletions
diff --git a/src/core/or/address_set.c b/src/core/or/address_set.c
index d618ffc3d6..fcddc55e9f 100644
--- a/src/core/or/address_set.c
+++ b/src/core/or/address_set.c
@@ -69,3 +69,77 @@ address_set_probably_contains(const address_set_t *set,
 {
   return bloomfilt_probably_contains(set, addr);
 }
+
+/* Length of the item is an address (IPv4 or IPv6) and a 2 byte port. We use
+ * 16 bytes for the address here (IPv6) since we do not know which family
+ * the given address in the item thus in the case of IPv4, the extra bytes
+ * are simply zeroes to accomodate. */
+#define BLOOMFILT_ADDR_PORT_ITEM_LEN (16 + sizeof(uint16_t))
+
+/** Build an item for the bloomfilter consisting of an address and port pair.
+ *
+ * If the given address is _not_ AF_INET or AF_INET6, then the item is an
+ * array of 0s.
+ *
+ * Return a pointer to a static buffer containing the item. Next call to this
+ * function invalidates its previous content. */
+static const uint8_t *
+build_addr_port_item(const tor_addr_t *addr, const uint16_t port)
+{
+  static uint8_t data[BLOOMFILT_ADDR_PORT_ITEM_LEN];
+
+  memset(data, 0, sizeof(data));
+  switch (tor_addr_family(addr)) {
+  case AF_INET:
+    memcpy(data, &addr->addr.in_addr.s_addr, 4);
+    break;
+  case AF_INET6:
+    memcpy(data, &addr->addr.in6_addr.s6_addr, 16);
+    break;
+  case AF_UNSPEC:
+    /* Leave the 0. */
+    break;
+  default:
+    /* LCOV_EXCL_START */
+    tor_fragile_assert();
+    /* LCOV_EXCL_STOP */
+  }
+
+  memcpy(data + 16, &port, sizeof(port));
+  return data;
+}
+
+/** Return a hash value for the given item that the bloomfilter will use. */
+static uint64_t
+bloomfilt_addr_port_hash(const struct sipkey *key,
+                         const void *item)
+{
+  return siphash24(item, BLOOMFILT_ADDR_PORT_ITEM_LEN, key);
+}
+
+/** Allocate and return an addr_port_set_t, suitable for holding up to
+ * max_address_guess distinct values. */
+addr_port_set_t *
+addr_port_set_new(int max_addresses_guess)
+{
+  uint8_t k[BLOOMFILT_KEY_LEN];
+  crypto_rand((void*)k, sizeof(k));
+  return bloomfilt_new(max_addresses_guess, bloomfilt_addr_port_hash, k);
+}
+
+/** Add an address and port pair to the given set. */
+void
+addr_port_set_add(addr_port_set_t *set, const tor_addr_t *addr, uint16_t port)
+{
+  bloomfilt_add(set, build_addr_port_item(addr, port));
+}
+
+/** Return true if the given address and port pair are in the set. Of course,
+ * this is a bloomfilter and thus in rare occasion, a false positive happens
+ * thus the "probably". */
+bool
+addr_port_set_probably_contains(const addr_port_set_t *set,
+                                const tor_addr_t *addr, uint16_t port)
+{
+  return !!bloomfilt_probably_contains(set, build_addr_port_item(addr, port));
+}