Merge #19628: net: change CNetAddr::ip to have flexible size

102867c587f5f7954232fb8ed8e85cda78bb4d32 net: change CNetAddr::ip to have flexible size (Vasil Dimov)
1ea57ad67406b3aaaef5254bc2fa7e4134f3a6df net: don't accept non-left-contiguous netmasks (Vasil Dimov)

Pull request description:

  (chopped off from #19031 to ease review)

  Before this change `CNetAddr::ip` was a fixed-size array of 16 bytes,
  not being able to store larger addresses (e.g. TORv3) and encoded
  smaller ones as 16-byte IPv6 addresses.

  Change its type to `prevector`, so that it can hold larger addresses and
  do not disguise non-IPv6 addresses as IPv6. So the IPv4 address
  `1.2.3.4` is now encoded as `01020304` instead of
  `00000000000000000000FFFF01020304`.

  Rename `CNetAddr::ip` to `CNetAddr::m_addr` because it is not an "IP" or
  "IP address" (TOR addresses are not IP addresses).

  In order to preserve backward compatibility with serialization (where
  e.g. `1.2.3.4` is serialized as `00000000000000000000FFFF01020304`)
  introduce `CNetAddr` dedicated legacy serialize/unserialize methods.

  Adjust `CSubNet` accordingly. Still use `CSubNet::netmask[]` of fixed 16
  bytes, but use the first 4 for IPv4 (not the last 4). Do not accept
  invalid netmasks that have 0-bits followed by 1-bits and only allow
  subnetting for IPv4 and IPv6.

  Co-authored-by: Carl Dong <contact@carldong.me>

ACKs for top commit:
  sipa:
    utACK 102867c587f5f7954232fb8ed8e85cda78bb4d32
  MarcoFalke:
    Concept ACK 102867c587f5f7954232fb8ed8e85cda78bb4d32
  ryanofsky:
    Code review ACK 102867c587f5f7954232fb8ed8e85cda78bb4d32. Just many suggested updates since last review. Thanks for following up on everything!
  jonatack:
    re-ACK 102867c587f5f7954232fb8ed8e85cda78bb4d32 diff review, code review, build/tests/running bitcoind with ipv4/ipv6/onion peers
  kallewoof:
    ACK 102867c587f5f7954232fb8ed8e85cda78bb4d32

Tree-SHA512: d60bf716cecf8d3e8146d2f90f897ebe956befb16f711a24cfe680024c5afc758fb9e4a0a22066b42f7630d52cf916318bedbcbc069ae07092d5250a11e8f762

1 files changed, 74 insertions, 0 deletions

diff --git a/src/test/net_tests.cpp b/src/test/net_tests.cpp
index 317000c771..917ae571f5 100644
--- a/src/test/net_tests.cpp
+++ b/src/test/net_tests.cpp
@@ -13,8 +13,10 @@
 #include <streams.h>
 #include <test/util/setup_common.h>
 #include <util/memory.h>
+#include <util/strencodings.h>
 #include <util/string.h>
 #include <util/system.h>
+#include <version.h>
 
 #include <boost/test/unit_test.hpp>
 
@@ -188,6 +190,78 @@ BOOST_AUTO_TEST_CASE(cnode_simple_test)
     BOOST_CHECK(pnode2->IsInboundConn() == true);
 }
 
+BOOST_AUTO_TEST_CASE(cnetaddr_basic)
+{
+    CNetAddr addr;
+
+    // IPv4, INADDR_ANY
+    BOOST_REQUIRE(LookupHost("0.0.0.0", addr, false));
+    BOOST_REQUIRE(!addr.IsValid());
+    BOOST_REQUIRE(addr.IsIPv4());
+
+    BOOST_CHECK(addr.IsBindAny());
+    BOOST_CHECK_EQUAL(addr.ToString(), "0.0.0.0");
+
+    // IPv4, INADDR_NONE
+    BOOST_REQUIRE(LookupHost("255.255.255.255", addr, false));
+    BOOST_REQUIRE(!addr.IsValid());
+    BOOST_REQUIRE(addr.IsIPv4());
+
+    BOOST_CHECK(!addr.IsBindAny());
+    BOOST_CHECK_EQUAL(addr.ToString(), "255.255.255.255");
+
+    // IPv4, casual
+    BOOST_REQUIRE(LookupHost("12.34.56.78", addr, false));
+    BOOST_REQUIRE(addr.IsValid());
+    BOOST_REQUIRE(addr.IsIPv4());
+
+    BOOST_CHECK(!addr.IsBindAny());
+    BOOST_CHECK_EQUAL(addr.ToString(), "12.34.56.78");
+
+    // IPv6, in6addr_any
+    BOOST_REQUIRE(LookupHost("::", addr, false));
+    BOOST_REQUIRE(!addr.IsValid());
+    BOOST_REQUIRE(addr.IsIPv6());
+
+    BOOST_CHECK(addr.IsBindAny());
+    BOOST_CHECK_EQUAL(addr.ToString(), "::");
+
+    // IPv6, casual
+    BOOST_REQUIRE(LookupHost("1122:3344:5566:7788:9900:aabb:ccdd:eeff", addr, false));
+    BOOST_REQUIRE(addr.IsValid());
+    BOOST_REQUIRE(addr.IsIPv6());
+
+    BOOST_CHECK(!addr.IsBindAny());
+    BOOST_CHECK_EQUAL(addr.ToString(), "1122:3344:5566:7788:9900:aabb:ccdd:eeff");
+
+    // TORv2
+    addr.SetSpecial("6hzph5hv6337r6p2.onion");
+    BOOST_REQUIRE(addr.IsValid());
+    BOOST_REQUIRE(addr.IsTor());
+
+    BOOST_CHECK(!addr.IsBindAny());
+    BOOST_CHECK_EQUAL(addr.ToString(), "6hzph5hv6337r6p2.onion");
+
+    // Internal
+    addr.SetInternal("esffpp");
+    BOOST_REQUIRE(!addr.IsValid()); // "internal" is considered invalid
+    BOOST_REQUIRE(addr.IsInternal());
+
+    BOOST_CHECK(!addr.IsBindAny());
+    BOOST_CHECK_EQUAL(addr.ToString(), "esffpvrt3wpeaygy.internal");
+}
+
+BOOST_AUTO_TEST_CASE(cnetaddr_serialize)
+{
+    CNetAddr addr;
+    CDataStream s(SER_NETWORK, PROTOCOL_VERSION);
+
+    addr.SetInternal("a");
+    s << addr;
+    BOOST_CHECK_EQUAL(HexStr(s), "fd6b88c08724ca978112ca1bbdcafac2");
+    s.clear();
+}
+
 // prior to PR #14728, this test triggers an undefined behavior
 BOOST_AUTO_TEST_CASE(ipv4_peer_with_ipv6_addrMe_test)
 {