Build and test most of the machinery needed for IPv6 virtualaddrmaps

With an IPv6 virtual address map, we can basically hand out a new
IPv6 address for _every_ address we connect to.  That'll be cool, and
will let us maybe get around prop205 issues.

This uses some fancy logic to try to make the code paths in the ipv4
and the ipv6 case as close as possible, and moves to randomly
generated addresses so we don't need to maintain those stupid counters
that will collide if Tor restarts but apps don't.

Also has some XXXX items to fix to make this useful. More design
needed.

1 files changed, 71 insertions, 0 deletions

diff --git a/src/test/test_addr.c b/src/test/test_addr.c
index d2b25e5e6..eea0fcde8 100644
--- a/src/test/test_addr.c
+++ b/src/test/test_addr.c
@@ -3,9 +3,11 @@
  * Copyright (c) 2007-2012, The Tor Project, Inc. */
 /* See LICENSE for licensing information */
 
+#define ADDRESSMAP_PRIVATE
 #include "orconfig.h"
 #include "or.h"
 #include "test.h"
+#include "addressmap.h"
 
 static void
 test_addr_basic(void)
@@ -773,6 +775,74 @@ test_addr_parse(void)
   ;
 }
 
+static void
+update_difference(int ipv6, uint8_t *d,
+                  const tor_addr_t *a, const tor_addr_t *b)
+{
+  const int n_bytes = ipv6 ? 16 : 4;
+  uint8_t a_tmp[4], b_tmp[4];
+  const uint8_t *ba, *bb;
+  int i;
+
+  if (ipv6) {
+    ba = tor_addr_to_in6_addr8(a);
+    bb = tor_addr_to_in6_addr8(b);
+  } else {
+    set_uint32(a_tmp, tor_addr_to_ipv4n(a));
+    set_uint32(b_tmp, tor_addr_to_ipv4n(b));
+    ba = a_tmp; bb = b_tmp;
+  }
+
+  for (i = 0; i < n_bytes; ++i) {
+    d[i] |= ba[i] ^ bb[i];
+  }
+}
+
+static void
+test_virtaddrmap(void *data)
+{
+  /* Let's start with a bunch of random addresses. */
+  int ipv6, bits, iter, b;
+  virtual_addr_conf_t cfg[2];
+  uint8_t bytes[16];
+
+  (void)data;
+
+  tor_addr_parse(&cfg[0].addr, "64.65.0.0");
+  tor_addr_parse(&cfg[1].addr, "3491:c0c0::");
+
+  for (ipv6 = 0; ipv6 <= 1; ++ipv6) {
+    for (bits = 0; bits < 18; ++bits) {
+      tor_addr_t last_a;
+      cfg[ipv6].bits = bits;
+      memset(bytes, 0, sizeof(bytes));
+      tor_addr_copy(&last_a, &cfg[ipv6].addr);
+      /* Generate 128 addresses with each addr/bits combination. */
+      for (iter = 0; iter < 128; ++iter) {
+        tor_addr_t a;
+
+        get_random_virtual_addr(&cfg[ipv6], &a);
+        //printf("%s\n", fmt_addr(&a));
+        /* Make sure that the first b bits match the configured network */
+        tt_int_op(0, ==, tor_addr_compare_masked(&a, &cfg[ipv6].addr,
+                                                 bits, CMP_EXACT));
+
+        /* And track which bits have been different between pairs of
+         * addresses */
+        update_difference(ipv6, bytes, &last_a, &a);
+      }
+
+      /* Now make sure all but the first 'bits' bits of bytes are true */
+      for (b = bits+1; b < (ipv6?128:32); ++b) {
+        tt_assert(1 & (bytes[b/8] >> (7-(b&7))));
+      }
+    }
+  }
+
+ done:
+  ;
+}
+
 #define ADDR_LEGACY(name)                                               \
   { #name, legacy_test_helper, 0, &legacy_setup, test_addr_ ## name }
 
@@ -780,6 +850,7 @@ struct testcase_t addr_tests[] = {
   ADDR_LEGACY(basic),
   ADDR_LEGACY(ip6_helpers),
   ADDR_LEGACY(parse),
+  { "virtaddr", test_virtaddrmap, 0, NULL, NULL },
   END_OF_TESTCASES
 };