From 4cb98fc3f329673f0de0acaf55418bdcf2b75419 Mon Sep 17 00:00:00 2001
From: DeckerSU <deckersu@protonmail.com>
Date: Mon, 7 Feb 2022 09:32:49 +0300
Subject: [PATCH] net, test: CNetAddr scoped ipv6 test coverage, rename scopeId
 to m_scope_id

backport of https://github.com/bitcoin/bitcoin/pull/19951 to our
codebase.
---
 src/netbase.cpp                    |  4 ++--
 src/netbase.h                      |  6 +++++-
 src/test-komodo/test_net_tests.cpp | 30 +++++++++++++++++++++++++++++-
 3 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/src/netbase.cpp b/src/netbase.cpp
index 67986524..40c5d952 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -714,7 +714,7 @@ CNetAddr::CNetAddr(const struct in_addr& ipv4Addr)
 CNetAddr::CNetAddr(const struct in6_addr& ipv6Addr, const uint32_t scope)
 {
     SetRaw(NET_IPV6, (const uint8_t*)&ipv6Addr);
-    scopeId = scope;
+    m_scope_id = scope;
 }
 
 CNetAddr::CNetAddr(const char *pszIp, bool fAllowLookup)
@@ -1308,7 +1308,7 @@ bool CService::GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const
         memset(paddrin6, 0, *addrlen);
         if (!GetIn6Addr(&paddrin6->sin6_addr))
             return false;
-        paddrin6->sin6_scope_id = scopeId;
+        paddrin6->sin6_scope_id = m_scope_id;
         paddrin6->sin6_family = AF_INET6;
         paddrin6->sin6_port = htons(port);
         return true;
diff --git a/src/netbase.h b/src/netbase.h
index f0d3df0a..27037b07 100644
--- a/src/netbase.h
+++ b/src/netbase.h
@@ -59,7 +59,11 @@ class CNetAddr
 {
     protected:
         unsigned char ip[16]; // in network byte order
-        uint32_t scopeId{0}; // for scoped/link-local ipv6 addresses
+        /**
+         * Scope id if scoped/link-local IPV6 address.
+         * See https://tools.ietf.org/html/rfc4007
+         */
+        uint32_t m_scope_id{0};
 
     public:
         CNetAddr();
diff --git a/src/test-komodo/test_net_tests.cpp b/src/test-komodo/test_net_tests.cpp
index 58161fe1..77520b2e 100644
--- a/src/test-komodo/test_net_tests.cpp
+++ b/src/test-komodo/test_net_tests.cpp
@@ -4,6 +4,7 @@
 
 #include <memory>
 #include <utility>
+#include <vector>
 
 namespace TestNetTests {
 
@@ -17,7 +18,7 @@ namespace TestNetTests {
     class CChildCService : public CService {
         public:
             explicit CChildCService(const CService &ipIn) : CService(ipIn) {};
-            uint32_t GetScopeId() { return scopeId; }
+            uint32_t GetScopeId() { return m_scope_id; }
     };
 
     // https://github.com/bitcoin/bitcoin/pull/14728 - fix uninitialized read when stringifying an addrLocal
@@ -80,4 +81,31 @@ namespace TestNetTests {
         ASSERT_TRUE(1);
 
     }
+
+    TEST(TestNetTests, cnetaddr_basic_scoped_link_local) {
+
+        CNetAddr addr;
+        std::vector<CNetAddr> vIP;
+        // IPv6, scoped/link-local. See https://tools.ietf.org/html/rfc4007
+        // We support non-negative decimal integers (uint32_t) as zone id indices.
+        // Test with a fairly-high value, e.g. 32, to avoid locally reserved ids.
+        const std::string link_local{"fe80::1"};
+        const std::string scoped_addr{link_local + "%32"};
+        ASSERT_TRUE(LookupHost(scoped_addr.c_str(), vIP, false));
+        addr = vIP[0];
+        ASSERT_TRUE(addr.IsValid());
+        ASSERT_TRUE(addr.IsIPv6());
+        //EXPECT_TRUE(!addr.IsBindAny());
+        const std::string addr_str{addr.ToString()};
+        EXPECT_TRUE(addr_str == scoped_addr || addr_str == "fe80:0:0:0:0:0:0:1");
+        // The fallback case "fe80:0:0:0:0:0:0:1" is needed for macOS 10.14/10.15 and (probably) later.
+        // Test that the delimiter "%" and default zone id of 0 can be omitted for the default scope.
+        const std::string link_local_zone{link_local + "%0"};
+        ASSERT_TRUE(LookupHost(link_local_zone.c_str(), vIP, false));
+        addr = vIP[0];
+        ASSERT_TRUE(addr.IsValid());
+        ASSERT_TRUE(addr.IsIPv6());
+        //EXPECT_TRUE(!addr.IsBindAny());
+        EXPECT_EQ(addr.ToString(), link_local);
+    }
 }
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