Remove build-time no-IPv6 setting

The year is 2014. All supported operating systems have IPv6 support,
most certainly at build time (this doesn't mean that IPv6 is configured,
of course).

If noone is exercising the functionality to disable it, that means it
doesn't get tested, and IMO it's better to get rid of it.

(it's also not used consistently in RPC/boost and Net code...)

configure.ac

@@ -62,13 +62,6 @@ AC_ARG_ENABLE([upnp-default],
   [use_upnp_default=$enableval],
   [use_upnp_default=no])
 
-dnl enable ipv6 support
-AC_ARG_ENABLE([ipv6],
-  [AS_HELP_STRING([--enable-ipv6],
-  [enable ipv6 (default is yes)])],
-  [use_ipv6=$enableval],
-  [use_ipv6=yes])
-
 AC_ARG_ENABLE(tests,
     AS_HELP_STRING([--enable-tests],[compile tests (default is yes)]),
     [use_tests=$enableval],
@@ -560,27 +553,6 @@ AC_MSG_RESULT($build_bitcoin_cli)
 dnl sets $bitcoin_enable_qt, $bitcoin_enable_qt_test, $bitcoin_enable_qt_dbus
 BITCOIN_QT_CONFIGURE([$use_pkgconfig], [qt4])
 
-
-if test x$use_ipv6 = xyes; then
-  dnl Check for ipv6 build requirements
-  AC_MSG_CHECKING(for operating system IPv6 support)
-  AC_TRY_LINK([
-  #if defined(_WINDOWS)
-  #include <winsock2.h>
-  #else
-  #include <sys/types.h>
-  #include <sys/socket.h>
-  #include <netinet/in.h>
-  #endif
-  ],[
-  #if !defined(_WINDOWS)
-  struct in6_addr ipv6Addr;
-  struct sockaddr_in6 addr;
-  #endif
-  int temp = socket(AF_INET6, SOCK_STREAM, 0);],
-  [AC_MSG_RESULT(yes); have_ipv6=yes; AC_DEFINE(HAVE_IPV6, 1, [Define this symbol if you have operating system IPv6 support])],
-  [AC_MSG_RESULT(no)]; have_ipv6=no)
-fi
 AC_LANG_POP
 
 if test "x$use_ccache" != "xno"; then
@@ -609,22 +581,6 @@ else
   AC_MSG_RESULT(no)
 fi
 
-dnl enable ipv6 support
-AC_MSG_CHECKING([whether to build with support for IPv6])
-if test x$have_ipv6 = xno; then
-  if test x$use_ipv6 = xyes; then
-     AC_MSG_ERROR([IPv6 requested, but cannot be built. use --disable-ipv6])
-  fi
-  AC_MSG_RESULT(no)
-else
-  if test x$use_ipv6 = xyes; then
-      AC_MSG_RESULT(yes)
-      AC_DEFINE([USE_IPV6],[1],[Define if IPv6 support should be compiled in])
-  else
-      AC_MSG_RESULT(no)
-  fi
-fi
-
 dnl enable upnp support
 AC_MSG_CHECKING([whether to build with support for UPnP])
 if test x$have_miniupnpc = xno; then
@@ -730,7 +686,6 @@ AC_SUBST(COPYRIGHT_YEAR, _COPYRIGHT_YEAR)
 
 AC_SUBST(USE_UPNP)
 AC_SUBST(USE_QRCODE)
-AC_SUBST(USE_IPV6)
 AC_SUBST(INCLUDES)
 AC_SUBST(BOOST_LIBS)
 AC_SUBST(TESTDEFS)

doc/build-unix.md

@@ -32,10 +32,6 @@ turned off by default.  See the configure options for upnp behavior desired:
 	--disable-upnp-default   (the default) UPnP support turned off by default at runtime
 	--enable-upnp-default    UPnP support turned on by default at runtime
 
-IPv6 support may be disabled by setting:
-
-	--disable-ipv6           Disable IPv6 support
-
 Licenses of statically linked libraries:
  Berkeley DB   New BSD license with additional requirement that linked
                software must be free open source

src/init.cpp

@@ -689,12 +689,6 @@ bool AppInit2(boost::thread_group& threadGroup)
                 SetLimited(net);
         }
     }
-#if defined(USE_IPV6)
-#if ! USE_IPV6
-    else
-        SetLimited(NET_IPV6);
-#endif
-#endif
 
     CService addrProxy;
     bool fProxy = false;
@@ -706,10 +700,8 @@ bool AppInit2(boost::thread_group& threadGroup)
         if (!IsLimited(NET_IPV4))
             SetProxy(NET_IPV4, addrProxy, nSocksVersion);
         if (nSocksVersion > 4) {
-#ifdef USE_IPV6
             if (!IsLimited(NET_IPV6))
                 SetProxy(NET_IPV6, addrProxy, nSocksVersion);
-#endif
             SetNameProxy(addrProxy, nSocksVersion);
         }
         fProxy = true;
@@ -751,9 +743,7 @@ bool AppInit2(boost::thread_group& threadGroup)
         else {
             struct in_addr inaddr_any;
             inaddr_any.s_addr = INADDR_ANY;
-#ifdef USE_IPV6
             fBound |= Bind(CService(in6addr_any, GetListenPort()), BF_NONE);
-#endif
             fBound |= Bind(CService(inaddr_any, GetListenPort()), !fBound ? BF_REPORT_ERROR : BF_NONE);
         }
         if (!fBound)

src/net.cpp

@@ -917,11 +917,7 @@ void ThreadSocketHandler()
         BOOST_FOREACH(SOCKET hListenSocket, vhListenSocket)
         if (hListenSocket != INVALID_SOCKET && FD_ISSET(hListenSocket, &fdsetRecv))
         {
-#ifdef USE_IPV6
             struct sockaddr_storage sockaddr;
-#else
-            struct sockaddr sockaddr;
-#endif
             socklen_t len = sizeof(sockaddr);
             SOCKET hSocket = accept(hListenSocket, (struct sockaddr*)&sockaddr, &len);
             CAddress addr;
@@ -1582,11 +1578,7 @@ bool BindListenPort(const CService &addrBind, string& strError)
     int nOne = 1;
 
     // Create socket for listening for incoming connections
-#ifdef USE_IPV6
     struct sockaddr_storage sockaddr;
-#else
-    struct sockaddr sockaddr;
-#endif
     socklen_t len = sizeof(sockaddr);
     if (!addrBind.GetSockAddr((struct sockaddr*)&sockaddr, &len))
     {
@@ -1627,7 +1619,6 @@ bool BindListenPort(const CService &addrBind, string& strError)
         return false;
     }
 
-#ifdef USE_IPV6
     // some systems don't have IPV6_V6ONLY but are always v6only; others do have the option
     // and enable it by default or not. Try to enable it, if possible.
     if (addrBind.IsIPv6()) {
@@ -1645,7 +1636,6 @@ bool BindListenPort(const CService &addrBind, string& strError)
         setsockopt(hListenSocket, IPPROTO_IPV6, nParameterId, (const char*)&nProtLevel, sizeof(int));
 #endif
     }
-#endif
 
     if (::bind(hListenSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
     {
@@ -1712,7 +1702,6 @@ void static Discover(boost::thread_group& threadGroup)
                 if (AddLocal(addr, LOCAL_IF))
                     LogPrintf("IPv4 %s: %s\n", ifa->ifa_name, addr.ToString());
             }
-#ifdef USE_IPV6
             else if (ifa->ifa_addr->sa_family == AF_INET6)
             {
                 struct sockaddr_in6* s6 = (struct sockaddr_in6*)(ifa->ifa_addr);
@@ -1720,7 +1709,6 @@ void static Discover(boost::thread_group& threadGroup)
                 if (AddLocal(addr, LOCAL_IF))
                     LogPrintf("IPv6 %s: %s\n", ifa->ifa_name, addr.ToString());
             }
-#endif
         }
         freeifaddrs(myaddrs);
     }

src/netbase.cpp

@@ -78,11 +78,7 @@ bool static LookupIntern(const char *pszName, std::vector<CNetAddr>& vIP, unsign
 
     aiHint.ai_socktype = SOCK_STREAM;
     aiHint.ai_protocol = IPPROTO_TCP;
-#ifdef USE_IPV6
     aiHint.ai_family = AF_UNSPEC;
-#else
-    aiHint.ai_family = AF_INET;
-#endif
 #ifdef WIN32
     aiHint.ai_flags = fAllowLookup ? 0 : AI_NUMERICHOST;
 #else
@@ -102,13 +98,11 @@ bool static LookupIntern(const char *pszName, std::vector<CNetAddr>& vIP, unsign
             vIP.push_back(CNetAddr(((struct sockaddr_in*)(aiTrav->ai_addr))->sin_addr));
         }
 
-#ifdef USE_IPV6
         if (aiTrav->ai_family == AF_INET6)
         {
             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in6));
             vIP.push_back(CNetAddr(((struct sockaddr_in6*)(aiTrav->ai_addr))->sin6_addr));
         }
-#endif
 
         aiTrav = aiTrav->ai_next;
     }
@@ -321,11 +315,7 @@ bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRe
 {
     hSocketRet = INVALID_SOCKET;
 
-#ifdef USE_IPV6
     struct sockaddr_storage sockaddr;
-#else
-    struct sockaddr sockaddr;
-#endif
     socklen_t len = sizeof(sockaddr);
     if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
         LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
@@ -585,12 +575,10 @@ CNetAddr::CNetAddr(const struct in_addr& ipv4Addr)
     memcpy(ip+12, &ipv4Addr, 4);
 }
 
-#ifdef USE_IPV6
 CNetAddr::CNetAddr(const struct in6_addr& ipv6Addr)
 {
     memcpy(ip, &ipv6Addr, 16);
 }
-#endif
 
 CNetAddr::CNetAddr(const char *pszIp, bool fAllowLookup)
 {
@@ -764,11 +752,7 @@ std::string CNetAddr::ToStringIP() const
     if (IsTor())
         return EncodeBase32(&ip[6], 10) + ".onion";
     CService serv(*this, 0);
-#ifdef USE_IPV6
     struct sockaddr_storage sockaddr;
-#else
-    struct sockaddr sockaddr;
-#endif
     socklen_t socklen = sizeof(sockaddr);
     if (serv.GetSockAddr((struct sockaddr*)&sockaddr, &socklen)) {
         char name[1025] = "";
@@ -813,13 +797,11 @@ bool CNetAddr::GetInAddr(struct in_addr* pipv4Addr) const
     return true;
 }
 
-#ifdef USE_IPV6
 bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const
 {
     memcpy(pipv6Addr, ip, 16);
     return true;
 }
-#endif
 
 // get canonical identifier of an address' group
 // no two connections will be attempted to addresses with the same group
@@ -993,23 +975,19 @@ CService::CService(const struct in_addr& ipv4Addr, unsigned short portIn) : CNet
 {
 }
 
-#ifdef USE_IPV6
 CService::CService(const struct in6_addr& ipv6Addr, unsigned short portIn) : CNetAddr(ipv6Addr), port(portIn)
 {
 }
-#endif
 
 CService::CService(const struct sockaddr_in& addr) : CNetAddr(addr.sin_addr), port(ntohs(addr.sin_port))
 {
     assert(addr.sin_family == AF_INET);
 }
 
-#ifdef USE_IPV6
 CService::CService(const struct sockaddr_in6 &addr) : CNetAddr(addr.sin6_addr), port(ntohs(addr.sin6_port))
 {
    assert(addr.sin6_family == AF_INET6);
 }
-#endif
 
 bool CService::SetSockAddr(const struct sockaddr *paddr)
 {
@@ -1017,11 +995,9 @@ bool CService::SetSockAddr(const struct sockaddr *paddr)
     case AF_INET:
         *this = CService(*(const struct sockaddr_in*)paddr);
         return true;
-#ifdef USE_IPV6
     case AF_INET6:
         *this = CService(*(const struct sockaddr_in6*)paddr);
         return true;
-#endif
     default:
         return false;
     }
@@ -1093,7 +1069,6 @@ bool CService::GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const
         paddrin->sin_port = htons(port);
         return true;
     }
-#ifdef USE_IPV6
     if (IsIPv6()) {
         if (*addrlen < (socklen_t)sizeof(struct sockaddr_in6))
             return false;
@@ -1106,7 +1081,6 @@ bool CService::GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const
         paddrin6->sin6_port = htons(port);
         return true;
     }
-#endif
     return false;
 }
 

src/netbase.h

@@ -77,10 +77,8 @@ class CNetAddr
         int GetReachabilityFrom(const CNetAddr *paddrPartner = NULL) const;
         void print() const;
 
-#ifdef USE_IPV6
         CNetAddr(const struct in6_addr& pipv6Addr);
         bool GetIn6Addr(struct in6_addr* pipv6Addr) const;
-#endif
 
         friend bool operator==(const CNetAddr& a, const CNetAddr& b);
         friend bool operator!=(const CNetAddr& a, const CNetAddr& b);
@@ -121,10 +119,8 @@ class CService : public CNetAddr
         std::string ToStringIPPort() const;
         void print() const;
 
-#ifdef USE_IPV6
         CService(const struct in6_addr& ipv6Addr, unsigned short port);
         CService(const struct sockaddr_in6& addr);
-#endif
 
         IMPLEMENT_SERIALIZE
             (