Merge pull request #2180 from majestrate/fix-2179-ipv6-upstream-dns-2023-05-20

libunbound ipv6 upstream dns syntax error

llarp/dns/server.cpp

@@ -177,10 +177,7 @@ namespace llarp::dns
       void
       AddUpstreamResolver(const SockAddr& dns)
       {
-        std::string str = dns.hostString();
-
-        if (const auto port = dns.getPort(); port != 53)
-          fmt::format_to(std::back_inserter(str), "@{}", port);
+        std::string str = fmt::format("{}@{}", dns.hostString(false), dns.getPort());
 
         if (auto err = ub_ctx_set_fwd(m_ctx, str.c_str()))
         {

llarp/ev/libuv.cpp

@@ -75,8 +75,11 @@ namespace llarp::uv
     std::optional<SockAddr>
     LocalAddr() const override
     {
-      auto addr = handle->sock<uvw::IPv4>();
-      return SockAddr{addr.ip, huint16_t{static_cast<uint16_t>(addr.port)}};
+      if (auto addr = handle->sock<uvw::IPv4>(); not addr.ip.empty())
+        return SockAddr{addr.ip, huint16_t{static_cast<uint16_t>(addr.port)}};
+      if (auto addr = handle->sock<uvw::IPv6>(); not addr.ip.empty())
+        return SockAddr{addr.ip, huint16_t{static_cast<uint16_t>(addr.port)}};
+      return std::nullopt;
     }
 
     std::optional<int>

llarp/net/sock_addr.cpp

@@ -290,25 +290,21 @@ namespace llarp
   }
 
   std::string
-  SockAddr::hostString() const
+  SockAddr::hostString(bool ipv6_brackets) const
   {
-    std::string str;
-    char buf[INET6_ADDRSTRLEN] = {0x0};
+    std::array<char, 128> buf{};
     if (isIPv4())
     {
-      // handle IPv4 mapped addrs
-      inet_ntop(AF_INET, &m_addr4.sin_addr.s_addr, buf, sizeof(buf));
-      str = buf;
+      // IPv4 mapped addrs
+      inet_ntop(AF_INET, &m_addr4.sin_addr.s_addr, buf.data(), buf.size());
+      return buf.data();
     }
-    else
-    {
-      inet_ntop(AF_INET6, &m_addr.sin6_addr.s6_addr, buf, sizeof(buf));
-      str.reserve(std::strlen(buf) + 2);
-      str.append("[");
-      str.append(buf);
-      str.append("]");
-    }
-    return str;
+
+    inet_ntop(AF_INET6, &m_addr.sin6_addr.s6_addr, buf.data(), buf.size());
+    if (not ipv6_brackets)
+      return buf.data();
+
+    return fmt::format("[{}]", buf.data());
   }
 
   bool

llarp/net/sock_addr.hpp

@@ -86,8 +86,10 @@ namespace llarp
     std::string
     ToString() const;
 
+    /// convert ip address to string; ipv6_brackets - if true or omitted we add [...] around the
+    /// IPv6 address, otherwise we return it bare.
     std::string
-    hostString() const;
+    hostString(bool ipv6_brackets = true) const;
 
     inline int
     Family() const