Problem: address parsing code is tied to the TCP code

Solution: Factor the code into a different file with a well defined API and add
unit tests.

CMakeLists.txt

@@ -603,6 +603,7 @@ set (cxx-sources
         udp_address.cpp
         scatter.cpp
         gather.cpp
+	ip_resolver.cpp
 		zap_client.cpp
 		# at least for VS, the header files must also be listed
 		address.hpp

Makefile.am

@@ -83,6 +83,8 @@ src_libzmq_la_SOURCES = \
 	src/io_thread.hpp \
 	src/ip.cpp \
 	src/ip.hpp \
+	src/ip_resolver.cpp \
+	src/ip_resolver.hpp \
 	src/ipc_address.cpp \
 	src/ipc_address.hpp \
 	src/ipc_connecter.cpp \
@@ -895,7 +897,8 @@ if ENABLE_STATIC
 test_apps += \
 	unittests/unittest_poller \
 	unittests/unittest_ypipe \
-	unittests/unittest_mtrie
+	unittests/unittest_mtrie \
+	unittests/unittest_ip_resolver
 
 unittests_unittest_poller_SOURCES = unittests/unittest_poller.cpp
 unittests_unittest_poller_CPPFLAGS = -I$(top_srcdir)/src ${UNITY_CPPFLAGS} $(CODE_COVERAGE_CPPFLAGS)
@@ -920,6 +923,14 @@ unittests_unittest_mtrie_LDADD = $(top_builddir)/src/.libs/libzmq.a \
 	${src_libzmq_la_LIBADD} \
 	${UNITY_LIBS} \
 	$(CODE_COVERAGE_LDFLAGS)
+
+unittests_unittest_ip_resolver_SOURCES = unittests/unittest_ip_resolver.cpp
+unittests_unittest_ip_resolver_CPPFLAGS = -I$(top_srcdir)/src ${UNITY_CPPFLAGS} $(CODE_COVERAGE_CPPFLAGS)
+unittests_unittest_ip_resolver_CXXFLAGS = $(CODE_COVERAGE_CXXFLAGS)
+unittests_unittest_ip_resolver_LDADD = $(top_builddir)/src/.libs/libzmq.a \
+	${src_libzmq_la_LIBADD} \
+	${UNITY_LIBS} \
+	$(CODE_COVERAGE_LDFLAGS)
 endif
 
 check_PROGRAMS = ${test_apps}

src/ip_resolver.cpp

+#include "precompiled.hpp"
+#include <string>
+#include <cstring>
+
+#include "macros.hpp"
+#include "stdint.hpp"
+#include "err.hpp"
+#include "ip.hpp"
+
+#ifndef ZMQ_HAVE_WINDOWS
+#include <sys/types.h>
+#include <arpa/inet.h>
+#include <netinet/tcp.h>
+#include <net/if.h>
+#include <netdb.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <stdlib.h>
+#endif
+
+#include "ip_resolver.hpp"
+
+zmq::ip_resolver_options_t::ip_resolver_options_t () :
+    bindable_wanted (false),
+    nic_name_allowed (false),
+    ipv6_wanted (false),
+    port_expected (false),
+    dns_allowed (false)
+{
+}
+
+zmq::ip_resolver_options_t &
+zmq::ip_resolver_options_t::bindable (bool bindable_)
+{
+    bindable_wanted = bindable_;
+
+    return *this;
+}
+
+zmq::ip_resolver_options_t &
+zmq::ip_resolver_options_t::allow_nic_name (bool allow_)
+{
+    nic_name_allowed = allow_;
+
+    return *this;
+}
+
+zmq::ip_resolver_options_t &zmq::ip_resolver_options_t::ipv6 (bool ipv6_)
+{
+    ipv6_wanted = ipv6_;
+
+    return *this;
+}
+
+//  If true we expect that the host will be followed by a colon and a port
+//  number or service name
+zmq::ip_resolver_options_t &
+zmq::ip_resolver_options_t::expect_port (bool expect_)
+{
+    port_expected = expect_;
+
+    return *this;
+}
+
+zmq::ip_resolver_options_t &zmq::ip_resolver_options_t::allow_dns (bool allow_)
+{
+    dns_allowed = allow_;
+
+    return *this;
+}
+
+bool zmq::ip_resolver_options_t::bindable ()
+{
+    return bindable_wanted;
+}
+
+bool zmq::ip_resolver_options_t::allow_nic_name ()
+{
+    return nic_name_allowed;
+}
+
+bool zmq::ip_resolver_options_t::ipv6 ()
+{
+    return ipv6_wanted;
+}
+
+bool zmq::ip_resolver_options_t::expect_port ()
+{
+    return port_expected;
+}
+
+bool zmq::ip_resolver_options_t::allow_dns ()
+{
+    return dns_allowed;
+}
+
+zmq::ip_resolver_t::ip_resolver_t (ip_resolver_options_t opts_) :
+    options (opts_)
+{
+}
+
+int zmq::ip_resolver_t::resolve (ip_addr_t *ip_addr_, const char *name_)
+{
+    std::string addr;
+    uint16_t port;
+
+    if (options.expect_port ()) {
+        //  We expect 'addr:port'. It's important to use str*r*chr to only get
+        //  the latest colon since IPv6 addresses use colons as delemiters.
+        const char *delim = strrchr (name_, ':');
+
+        if (delim == NULL) {
+            errno = EINVAL;
+            return -1;
+        }
+
+        addr = std::string (name_, delim - name_);
+        std::string port_str = std::string (delim + 1);
+
+        if (port_str == "*" || port_str == "0") {
+            //  Resolve wildcard to 0 to allow autoselection of port
+            port = 0;
+        } else {
+            //  Parse the port number (0 is not a valid port).
+            port = (uint16_t) atoi (port_str.c_str ());
+            if (port == 0) {
+                errno = EINVAL;
+                return -1;
+            }
+        }
+    } else {
+        addr = std::string (name_);
+        port = 0;
+    }
+
+    //  Trim any square brackets surrounding the address. Used for
+    //  IPv6 addresses to remove the confusion with the port
+    //  delimiter. Should we validate that the brackets are present if
+    //  'addr' contains ':' ?
+    if (addr.size () >= 2 && addr[0] == '[' && addr[addr.size () - 1] == ']') {
+        addr = addr.substr (1, addr.size () - 2);
+    }
+
+    //  Look for an interface name / zone_id in the address
+    //  Reference: https://tools.ietf.org/html/rfc4007
+    std::size_t pos = addr.rfind ('%');
+    uint32_t zone_id = 0;
+
+    if (pos != std::string::npos) {
+        std::string if_str = addr.substr (pos + 1);
+        addr = addr.substr (0, pos);
+
+        if (isalpha (if_str.at (0))) {
+            zone_id = do_if_nametoindex (if_str.c_str ());
+        } else {
+            zone_id = (uint32_t) atoi (if_str.c_str ());
+        }
+
+        if (zone_id == 0) {
+            errno = EINVAL;
+            return -1;
+        }
+    }
+
+    bool resolved = false;
+    const char *addr_str = addr.c_str ();
+
+    if (options.bindable () && addr == "*") {
+        //  Return an ANY address
+        resolved = true;
+
+        if (options.ipv6 ()) {
+            sockaddr_in6 *ip6_addr = &ip_addr_->ipv6;
+
+            memset (ip6_addr, 0, sizeof (*ip6_addr));
+            ip6_addr->sin6_family = AF_INET6;
+#ifdef ZMQ_HAVE_VXWORKS
+            struct in6_addr newaddr = IN6ADDR_ANY_INIT;
+            memcpy (&ip6_addr->sin6_addr, &newaddr, sizeof (in6_addr));
+#else
+            memcpy (&ip6_addr->sin6_addr, &in6addr_any, sizeof (in6addr_any));
+#endif
+        } else {
+            sockaddr_in *ip4_addr = &ip_addr_->ipv4;
+            memset (ip4_addr, 0, sizeof (*ip4_addr));
+            ip4_addr->sin_family = AF_INET;
+            ip4_addr->sin_addr.s_addr = htonl (INADDR_ANY);
+        }
+    }
+
+    if (!resolved && options.allow_nic_name ()) {
+        //  Try to resolve the string as a NIC name.
+        int rc = resolve_nic_name (ip_addr_, addr_str);
+
+        if (rc == 0) {
+            resolved = true;
+        } else if (errno != ENODEV) {
+            return rc;
+        }
+    }
+
+    if (!resolved) {
+        int rc = resolve_getaddrinfo (ip_addr_, addr_str);
+
+        if (rc != 0) {
+            return rc;
+        }
+        resolved = true;
+    }
+
+    //  Store the port into the structure. We could get 'getaddrinfo' to do it
+    //  for us but since we don't resolve service names it's a bit overkill and
+    //  we'd still have to do it manually when the address is resolved by
+    //  'resolve_nic_name'
+    if (ip_addr_->generic.sa_family == AF_INET6) {
+        ip_addr_->ipv6.sin6_port = htons (port);
+        ip_addr_->ipv6.sin6_scope_id = zone_id;
+    } else {
+        ip_addr_->ipv4.sin_port = htons (port);
+    }
+
+    assert (resolved == true);
+    return 0;
+}
+
+int zmq::ip_resolver_t::resolve_getaddrinfo (ip_addr_t *ip_addr_,
+                                             const char *addr_)
+{
+#if defined ZMQ_HAVE_OPENVMS && defined __ia64
+    __addrinfo64 *res = NULL;
+    __addrinfo64 req;
+#else
+    addrinfo *res = NULL;
+    addrinfo req;
+#endif
+
+    memset (&req, 0, sizeof (req));
+
+    //  Choose IPv4 or IPv6 protocol family. Note that IPv6 allows for
+    //  IPv4-in-IPv6 addresses.
+    req.ai_family = options.ipv6 () ? AF_INET6 : AF_INET;
+
+    //  Arbitrary, not used in the output, but avoids duplicate results.
+    req.ai_socktype = SOCK_STREAM;
+
+    req.ai_flags = 0;
+
+    if (options.bindable ()) {
+        req.ai_flags |= AI_PASSIVE;
+    }
+
+    if (!options.allow_dns ()) {
+        req.ai_flags |= AI_NUMERICHOST;
+    }
+
+#if defined AI_V4MAPPED
+    //  In this API we only require IPv4-mapped addresses when
+    //  no native IPv6 interfaces are available (~AI_ALL).
+    //  This saves an additional DNS roundtrip for IPv4 addresses.
+    if (req.ai_family == AF_INET6) {
+        req.ai_flags |= AI_V4MAPPED;
+    }
+#endif
+
+    //  Resolve the literal address. Some of the error info is lost in case
+    //  of error, however, there's no way to report EAI errors via errno.
+    int rc = do_getaddrinfo (addr_, NULL, &req, &res);
+
+#if defined AI_V4MAPPED
+    // Some OS do have AI_V4MAPPED defined but it is not supported in getaddrinfo()
+    // returning EAI_BADFLAGS. Detect this and retry
+    if (rc == EAI_BADFLAGS && (req.ai_flags & AI_V4MAPPED)) {
+        req.ai_flags &= ~AI_V4MAPPED;
+        rc = do_getaddrinfo (addr_, NULL, &req, &res);
+    }
+#endif
+
+#if defined ZMQ_HAVE_WINDOWS
+    //  Resolve specific case on Windows platform when using IPv4 address
+    //  with ZMQ_IPv6 socket option.
+    if ((req.ai_family == AF_INET6) && (rc == WSAHOST_NOT_FOUND)) {
+        req.ai_family = AF_INET;
+        rc = do_getaddrinfo (addr_, NULL, &req, &res);
+    }
+#endif
+
+    if (rc) {
+        switch (rc) {
+            case EAI_MEMORY:
+                errno = ENOMEM;
+                break;
+            default:
+                if (options.bindable ()) {
+                    errno = ENODEV;
+                } else {
+                    errno = EINVAL;
+                }
+                break;
+        }
+        return -1;
+    }
+
+    //  Use the first result.
+    zmq_assert (res != NULL);
+    zmq_assert ((size_t) res->ai_addrlen <= sizeof (*ip_addr_));
+    memcpy (ip_addr_, res->ai_addr, res->ai_addrlen);
+
+    //  Cleanup getaddrinfo after copying the possibly referenced result.
+    do_freeaddrinfo (res);
+
+    return 0;
+}
+
+#ifdef ZMQ_HAVE_SOLARIS
+#include <sys/sockio.h>
+
+//  On Solaris platform, network interface name can be queried by ioctl.
+int zmq::ip_resolver_t::resolve_nic_name (ip_addr_t *ip_addr_, const char *nic_)
+{
+    //  Create a socket.
+    const int fd = open_socket (AF_INET, SOCK_DGRAM, 0);
+    errno_assert (fd != -1);
+
+    //  Retrieve number of interfaces.
+    lifnum ifn;
+    ifn.lifn_family = AF_INET;
+    ifn.lifn_flags = 0;
+    int rc = ioctl (fd, SIOCGLIFNUM, (char *) &ifn);
+    errno_assert (rc != -1);
+
+    //  Allocate memory to get interface names.
+    const size_t ifr_size = sizeof (struct lifreq) * ifn.lifn_count;
+    char *ifr = (char *) malloc (ifr_size);
+    alloc_assert (ifr);
+
+    //  Retrieve interface names.
+    lifconf ifc;
+    ifc.lifc_family = AF_INET;
+    ifc.lifc_flags = 0;
+    ifc.lifc_len = ifr_size;
+    ifc.lifc_buf = ifr;
+    rc = ioctl (fd, SIOCGLIFCONF, (char *) &ifc);
+    errno_assert (rc != -1);
+
+    //  Find the interface with the specified name and AF_INET family.
+    bool found = false;
+    lifreq *ifrp = ifc.lifc_req;
+    for (int n = 0; n < (int) (ifc.lifc_len / sizeof (lifreq)); n++, ifrp++) {
+        if (!strcmp (nic_, ifrp->lifr_name)) {
+            rc = ioctl (fd, SIOCGLIFADDR, (char *) ifrp);
+            errno_assert (rc != -1);
+            if (ifrp->lifr_addr.ss_family == AF_INET) {
+                ip_addr_->ipv4 = *(sockaddr_in *) &ifrp->lifr_addr;
+                found = true;
+                break;
+            }
+        }
+    }
+
+    //  Clean-up.
+    free (ifr);
+    close (fd);
+
+    if (!found) {
+        errno = ENODEV;
+        return -1;
+    }
+    return 0;
+}
+
+#elif defined ZMQ_HAVE_AIX || defined ZMQ_HAVE_HPUX                            \
+  || defined ZMQ_HAVE_ANDROID || defined ZMQ_HAVE_VXWORKS
+#include <sys/ioctl.h>
+#ifdef ZMQ_HAVE_VXWORKS
+#include <ioLib.h>
+#endif
+
+int zmq::ip_resolver_t::resolve_nic_name (ip_addr_t *ip_addr_, const char *nic_)
+{
+#if defined ZMQ_HAVE_AIX || defined ZMQ_HAVE_HPUX
+    // IPv6 support not implemented for AIX or HP/UX.
+    if (options.ipv6 ()) {
+        errno = ENODEV;
+        return -1;
+    }
+#endif
+
+    //  Create a socket.
+    const int sd =
+      open_socket (options.ipv6 () ? AF_INET6 : AF_INET, SOCK_DGRAM, 0);
+    errno_assert (sd != -1);
+
+    struct ifreq ifr;
+
+    //  Copy interface name for ioctl get.
+    strncpy (ifr.ifr_name, nic_, sizeof (ifr.ifr_name));
+
+    //  Fetch interface address.
+    const int rc = ioctl (sd, SIOCGIFADDR, (caddr_t) &ifr, sizeof (ifr));
+
+    //  Clean up.
+    close (sd);
+
+    if (rc == -1) {
+        errno = ENODEV;
+        return -1;
+    }
+
+    const int family = ifr.ifr_addr.sa_family;
+    if (family == (options.ipv6 () ? AF_INET6 : AF_INET)
+        && !strcmp (nic_, ifr.ifr_name)) {
+        memcpy (ip_addr_, &ifr.ifr_addr,
+                (family == AF_INET) ? sizeof (struct sockaddr_in)
+                                    : sizeof (struct sockaddr_in6));
+    } else {
+        errno = ENODEV;
+        return -1;
+    }
+
+    return 0;
+}
+
+#elif ((defined ZMQ_HAVE_LINUX || defined ZMQ_HAVE_FREEBSD                     \
+        || defined ZMQ_HAVE_OSX || defined ZMQ_HAVE_OPENBSD                    \
+        || defined ZMQ_HAVE_QNXNTO || defined ZMQ_HAVE_NETBSD                  \
+        || defined ZMQ_HAVE_DRAGONFLY || defined ZMQ_HAVE_GNU)                 \
+       && defined ZMQ_HAVE_IFADDRS)
+
+#include <ifaddrs.h>
+
+//  On these platforms, network interface name can be queried
+//  using getifaddrs function.
+int zmq::ip_resolver_t::resolve_nic_name (ip_addr_t *ip_addr_, const char *nic_)
+{
+    //  Get the addresses.
+    ifaddrs *ifa = NULL;
+    int rc = 0;
+    const int max_attempts = 10;
+    const int backoff_msec = 1;
+    for (int i = 0; i < max_attempts; i++) {
+        rc = getifaddrs (&ifa);
+        if (rc == 0 || (rc < 0 && errno != ECONNREFUSED))
+            break;
+        usleep ((backoff_msec << i) * 1000);
+    }
+
+    if (rc != 0 && ((errno == EINVAL) || (errno == EOPNOTSUPP))) {
+        // Windows Subsystem for Linux compatibility
+        errno = ENODEV;
+        return -1;
+    }
+    errno_assert (rc == 0);
+    zmq_assert (ifa != NULL);
+
+    //  Find the corresponding network interface.
+    bool found = false;
+    for (ifaddrs *ifp = ifa; ifp != NULL; ifp = ifp->ifa_next) {
+        if (ifp->ifa_addr == NULL)
+            continue;
+
+        const int family = ifp->ifa_addr->sa_family;
+        if (family == (options.ipv6 () ? AF_INET6 : AF_INET)
+            && !strcmp (nic_, ifp->ifa_name)) {
+            memcpy (ip_addr_, ifp->ifa_addr,
+                    (family == AF_INET) ? sizeof (struct sockaddr_in)
+                                        : sizeof (struct sockaddr_in6));
+            found = true;
+            break;
+        }
+    }
+
+    //  Clean-up;
+    freeifaddrs (ifa);
+
+    if (!found) {
+        errno = ENODEV;
+        return -1;
+    }
+    return 0;
+}
+
+#elif (defined ZMQ_HAVE_WINDOWS)
+
+#include <netioapi.h>
+
+int zmq::ip_resolver_t::get_interface_name (unsigned long index,
+                                            char **dest) const
+{
+#ifdef ZMQ_HAVE_WINDOWS_UWP
+    char *buffer = (char *) malloc (1024);
+#else
+    char *buffer = (char *) malloc (IF_MAX_STRING_SIZE);
+#endif
+    alloc_assert (buffer);
+
+    char *if_name_result = NULL;
+
+#if !defined ZMQ_HAVE_WINDOWS_TARGET_XP && !defined ZMQ_HAVE_WINDOWS_UWP
+    if_name_result = if_indextoname (index, buffer);
+#endif
+
+    if (if_name_result == NULL) {
+        free (buffer);
+        return -1;
+    }
+
+    *dest = buffer;
+    return 0;
+}
+
+int zmq::ip_resolver_t::wchar_to_utf8 (const WCHAR *src, char **dest) const
+{
+    int rc;
+    int buffer_len =
+      WideCharToMultiByte (CP_UTF8, 0, src, -1, NULL, 0, NULL, 0);
+
+    char *buffer = (char *) malloc (buffer_len);
+    alloc_assert (buffer);
+
+    rc = WideCharToMultiByte (CP_UTF8, 0, src, -1, buffer, buffer_len, NULL, 0);
+
+    if (rc == 0) {
+        free (buffer);
+        return -1;
+    }
+
+    *dest = buffer;
+    return 0;
+}
+
+int zmq::ip_resolver_t::resolve_nic_name (ip_addr_t *ip_addr_, const char *nic_)
+{
+    int rc;
+    bool found = false;
+    const int max_attempts = 10;
+
+    int iterations = 0;
+    IP_ADAPTER_ADDRESSES *addresses = NULL;
+    IP_ADAPTER_ADDRESSES *current_addresses = NULL;
+    unsigned long out_buf_len = sizeof (IP_ADAPTER_ADDRESSES);
+
+    do {
+        addresses = (IP_ADAPTER_ADDRESSES *) malloc (out_buf_len);
+        alloc_assert (addresses);
+
+        rc =
+          GetAdaptersAddresses (AF_UNSPEC,
+                                GAA_FLAG_SKIP_ANYCAST | GAA_FLAG_SKIP_MULTICAST
+                                  | GAA_FLAG_SKIP_DNS_SERVER,
+                                NULL, addresses, &out_buf_len);
+        if (rc == ERROR_BUFFER_OVERFLOW) {
+            free (addresses);
+            addresses = NULL;
+        } else {
+            break;
+        }
+        iterations++;
+    } while ((rc == ERROR_BUFFER_OVERFLOW) && (iterations < max_attempts));
+
+    if (rc == 0) {
+        current_addresses = addresses;
+        while (current_addresses) {
+            char *if_name = NULL;
+            char *if_friendly_name = NULL;
+            int str_rc1, str_rc2;
+
+            str_rc1 = get_interface_name (current_addresses->IfIndex, &if_name);
+            str_rc2 = wchar_to_utf8 (current_addresses->FriendlyName,
+                                     &if_friendly_name);
+
+            //  Find a network adapter by its "name" or "friendly name"
+            if (((str_rc1 == 0) && (!strcmp (nic_, if_name)))
+                || ((str_rc2 == 0) && (!strcmp (nic_, if_friendly_name)))) {
+                //  Iterate over all unicast addresses bound to the current network interface
+                IP_ADAPTER_UNICAST_ADDRESS *unicast_address =
+                  current_addresses->FirstUnicastAddress;
+                IP_ADAPTER_UNICAST_ADDRESS *current_unicast_address =
+                  unicast_address;
+
+                while (current_unicast_address) {
+                    ADDRESS_FAMILY family =
+                      current_unicast_address->Address.lpSockaddr->sa_family;
+
+                    if (family == (options.ipv6 () ? AF_INET6 : AF_INET)) {
+                        memcpy (
+                          ip_addr_, current_unicast_address->Address.lpSockaddr,
+                          (family == AF_INET) ? sizeof (struct sockaddr_in)
+                                              : sizeof (struct sockaddr_in6));
+                        found = true;
+                        break;
+                    }
+
+                    current_unicast_address = current_unicast_address->Next;
+                }
+
+                if (found)
+                    break;
+            }
+
+            if (str_rc1 == 0)
+                free (if_name);
+            if (str_rc2 == 0)
+                free (if_friendly_name);
+
+            current_addresses = current_addresses->Next;
+        }
+
+        free (addresses);
+    }
+
+    if (!found) {
+        errno = ENODEV;
+        return -1;
+    }
+    return 0;
+}
+
+#else
+
+//  On other platforms we assume there are no sane interface names.
+int zmq::ip_resolver_t::resolve_nic_name (ip_addr_t *ip_addr_, const char *nic_)
+{
+    LIBZMQ_UNUSED (ip_addr_);
+    LIBZMQ_UNUSED (nic_);
+
+    errno = ENODEV;
+    return -1;
+}
+
+#endif
+
+int zmq::ip_resolver_t::do_getaddrinfo (const char *node_,
+                                        const char *service_,
+                                        const struct addrinfo *hints_,
+                                        struct addrinfo **res_)
+{
+    return getaddrinfo (node_, service_, hints_, res_);
+}
+
+void zmq::ip_resolver_t::do_freeaddrinfo (struct addrinfo *res_)
+{
+    freeaddrinfo (res_);
+}
+
+unsigned int zmq::ip_resolver_t::do_if_nametoindex (const char *ifname_)
+{
+#if !defined ZMQ_HAVE_WINDOWS_TARGET_XP && !defined ZMQ_HAVE_WINDOWS_UWP       \
+  && !defined ZMQ_HAVE_VXWORKS
+    return if_nametoindex (ifname_);
+#else
+    // The function 'if_nametoindex' is not supported on Windows XP.
+    // If we are targeting XP using a vxxx_xp toolset then fail.
+    // This is brutal as this code could be run on later windows clients
+    // meaning the IPv6 zone_id cannot have an interface name.
+    // This could be fixed with a runtime check.
+    return 0;
+#endif
+}

src/ip_resolver.hpp

+/*
+    Copyright (c) 2007-2018 Contributors as noted in the AUTHORS file
+
+    This file is part of libzmq, the ZeroMQ core engine in C++.
+
+    libzmq is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License (LGPL) as published
+    by the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    As a special exception, the Contributors give you permission to link
+    this library with independent modules to produce an executable,
+    regardless of the license terms of these independent modules, and to
+    copy and distribute the resulting executable under terms of your choice,
+    provided that you also meet, for each linked independent module, the
+    terms and conditions of the license of that module. An independent
+    module is a module which is not derived from or based on this library.
+    If you modify this library, you must extend this exception to your
+    version of the library.
+
+    libzmq is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_IP_RESOLVER_HPP_INCLUDED__
+#define __ZMQ_IP_RESOLVER_HPP_INCLUDED__
+
+#if !defined ZMQ_HAVE_WINDOWS
+#include <sys/socket.h>
+#include <netinet/in.h>
+#endif
+
+namespace zmq
+{
+union ip_addr_t
+{
+    sockaddr generic;
+    sockaddr_in ipv4;
+    sockaddr_in6 ipv6;
+};
+
+class ip_resolver_options_t
+{
+  public:
+    ip_resolver_options_t ();
+
+    ip_resolver_options_t &bindable (bool bindable_);
+    ip_resolver_options_t &allow_nic_name (bool allow_);
+    ip_resolver_options_t &ipv6 (bool ipv6_);
+    ip_resolver_options_t &expect_port (bool expect_);
+    ip_resolver_options_t &allow_dns (bool allow_);
+
+    bool bindable ();
+    bool allow_nic_name ();
+    bool ipv6 ();
+    bool expect_port ();
+    bool allow_dns ();
+
+  private:
+    bool bindable_wanted;
+    bool nic_name_allowed;
+    bool ipv6_wanted;
+    bool port_expected;
+    bool dns_allowed;
+};
+
+class ip_resolver_t
+{
+  public:
+    ip_resolver_t (ip_resolver_options_t opts_);
+
+    int resolve (ip_addr_t *ip_addr_, const char *name_);
+
+  protected:
+    ip_resolver_options_t options;
+
+    int resolve_nic_name (ip_addr_t *ip_addr_, const char *nic_);
+    int resolve_getaddrinfo (ip_addr_t *ip_addr_, const char *addr_);
+
+#if defined ZMQ_HAVE_WINDOWS
+    int get_interface_name (unsigned long index, char **dest) const;
+    int wchar_to_utf8 (const WCHAR *src, char **dest) const;
+#endif
+
+    //  Virtual functions that are overriden in tests
+    virtual int do_getaddrinfo (const char *node_,
+                                const char *service_,
+                                const struct addrinfo *hints_,
+                                struct addrinfo **res_);
+
+    virtual void do_freeaddrinfo (struct addrinfo *res_);
+
+    virtual unsigned int do_if_nametoindex (const char *ifname_);
+};
+}
+
+#endif

src/tcp_address.cpp

@@ -48,547 +48,6 @@
 #include <stdlib.h>
 #endif
 
-#ifdef ZMQ_HAVE_SOLARIS
-#include <sys/sockio.h>
-
-//  On Solaris platform, network interface name can be queried by ioctl.
-int zmq::tcp_address_t::resolve_nic_name (const char *nic_,
-                                          bool ipv6_,
-                                          bool is_src_)
-{
-    //  TODO: Unused parameter, IPv6 support not implemented for Solaris.
-    LIBZMQ_UNUSED (ipv6_);
-
-    //  Create a socket.
-    const int fd = open_socket (AF_INET, SOCK_DGRAM, 0);
-    errno_assert (fd != -1);
-
-    //  Retrieve number of interfaces.
-    lifnum ifn;
-    ifn.lifn_family = AF_INET;
-    ifn.lifn_flags = 0;
-    int rc = ioctl (fd, SIOCGLIFNUM, (char *) &ifn);
-    errno_assert (rc != -1);
-
-    //  Allocate memory to get interface names.
-    const size_t ifr_size = sizeof (struct lifreq) * ifn.lifn_count;
-    char *ifr = (char *) malloc (ifr_size);
-    alloc_assert (ifr);
-
-    //  Retrieve interface names.
-    lifconf ifc;
-    ifc.lifc_family = AF_INET;
-    ifc.lifc_flags = 0;
-    ifc.lifc_len = ifr_size;
-    ifc.lifc_buf = ifr;
-    rc = ioctl (fd, SIOCGLIFCONF, (char *) &ifc);
-    errno_assert (rc != -1);
-
-    //  Find the interface with the specified name and AF_INET family.
-    bool found = false;
-    lifreq *ifrp = ifc.lifc_req;
-    for (int n = 0; n < (int) (ifc.lifc_len / sizeof (lifreq)); n++, ifrp++) {
-        if (!strcmp (nic_, ifrp->lifr_name)) {
-            rc = ioctl (fd, SIOCGLIFADDR, (char *) ifrp);
-            errno_assert (rc != -1);
-            if (ifrp->lifr_addr.ss_family == AF_INET) {
-                if (is_src_)
-                    source_address.ipv4 = *(sockaddr_in *) &ifrp->lifr_addr;
-                else
-                    address.ipv4 = *(sockaddr_in *) &ifrp->lifr_addr;
-                found = true;
-                break;
-            }
-        }
-    }
-
-    //  Clean-up.
-    free (ifr);
-    close (fd);
-
-    if (!found) {
-        errno = ENODEV;
-        return -1;
-    }
-    return 0;
-}
-
-#elif defined ZMQ_HAVE_AIX || defined ZMQ_HAVE_HPUX                            \
-  || defined ZMQ_HAVE_ANDROID || defined ZMQ_HAVE_VXWORKS
-#include <sys/ioctl.h>
-#ifdef ZMQ_HAVE_VXWORKS
-#include <ioLib.h>
-#endif
-
-int zmq::tcp_address_t::resolve_nic_name (const char *nic_,
-                                          bool ipv6_,
-                                          bool is_src_)
-{
-#if defined ZMQ_HAVE_AIX || defined ZMQ_HAVE_HPUX
-    // IPv6 support not implemented for AIX or HP/UX.
-    if (ipv6_) {
-        errno = ENODEV;
-        return -1;
-    }
-#endif
-
-    //  Create a socket.
-    const int sd = open_socket (ipv6_ ? AF_INET6 : AF_INET, SOCK_DGRAM, 0);
-    errno_assert (sd != -1);
-
-    struct ifreq ifr;
-
-    //  Copy interface name for ioctl get.
-    strncpy (ifr.ifr_name, nic_, sizeof (ifr.ifr_name));
-
-    //  Fetch interface address.
-    const int rc = ioctl (sd, SIOCGIFADDR, (caddr_t) &ifr, sizeof (ifr));
-
-    //  Clean up.
-    close (sd);
-
-    if (rc == -1) {
-        errno = ENODEV;
-        return -1;
-    }
-
-    const int family = ifr.ifr_addr.sa_family;
-    if (family == (ipv6_ ? AF_INET6 : AF_INET)
-        && !strcmp (nic_, ifr.ifr_name)) {
-        if (is_src_)
-            memcpy (&source_address, &ifr.ifr_addr,
-                    (family == AF_INET) ? sizeof (struct sockaddr_in)
-                                        : sizeof (struct sockaddr_in6));
-        else
-            memcpy (&address, &ifr.ifr_addr,
-                    (family == AF_INET) ? sizeof (struct sockaddr_in)
-                                        : sizeof (struct sockaddr_in6));
-    } else {
-        errno = ENODEV;
-        return -1;
-    }
-
-    return 0;
-}
-
-#elif ((defined ZMQ_HAVE_LINUX || defined ZMQ_HAVE_FREEBSD                     \
-        || defined ZMQ_HAVE_OSX || defined ZMQ_HAVE_OPENBSD                    \
-        || defined ZMQ_HAVE_QNXNTO || defined ZMQ_HAVE_NETBSD                  \
-        || defined ZMQ_HAVE_DRAGONFLY || defined ZMQ_HAVE_GNU)                 \
-       && defined ZMQ_HAVE_IFADDRS)
-
-#include <ifaddrs.h>
-
-//  On these platforms, network interface name can be queried
-//  using getifaddrs function.
-int zmq::tcp_address_t::resolve_nic_name (const char *nic_,
-                                          bool ipv6_,
-                                          bool is_src_)
-{
-    //  Get the addresses.
-    ifaddrs *ifa = NULL;
-    int rc = 0;
-    const int max_attempts = 10;
-    const int backoff_msec = 1;
-    for (int i = 0; i < max_attempts; i++) {
-        rc = getifaddrs (&ifa);
-        if (rc == 0 || (rc < 0 && errno != ECONNREFUSED))
-            break;
-        usleep ((backoff_msec << i) * 1000);
-    }
-
-    if (rc != 0 && ((errno == EINVAL) || (errno == EOPNOTSUPP))) {
-        // Windows Subsystem for Linux compatibility
-        LIBZMQ_UNUSED (nic_);
-        LIBZMQ_UNUSED (ipv6_);
-
-        errno = ENODEV;
-        return -1;
-    }
-    errno_assert (rc == 0);
-    zmq_assert (ifa != NULL);
-
-    //  Find the corresponding network interface.
-    bool found = false;
-    for (ifaddrs *ifp = ifa; ifp != NULL; ifp = ifp->ifa_next) {
-        if (ifp->ifa_addr == NULL)
-            continue;
-
-        const int family = ifp->ifa_addr->sa_family;
-        if (family == (ipv6_ ? AF_INET6 : AF_INET)
-            && !strcmp (nic_, ifp->ifa_name)) {
-            if (is_src_)
-                memcpy (&source_address, ifp->ifa_addr,
-                        (family == AF_INET) ? sizeof (struct sockaddr_in)
-                                            : sizeof (struct sockaddr_in6));
-            else
-                memcpy (&address, ifp->ifa_addr,
-                        (family == AF_INET) ? sizeof (struct sockaddr_in)
-                                            : sizeof (struct sockaddr_in6));
-            found = true;
-            break;
-        }
-    }
-
-    //  Clean-up;
-    freeifaddrs (ifa);
-
-    if (!found) {
-        errno = ENODEV;
-        return -1;
-    }
-    return 0;
-}
-
-#elif (defined ZMQ_HAVE_WINDOWS)
-
-#include <netioapi.h>
-
-int zmq::tcp_address_t::get_interface_name (unsigned long index,
-                                            char **dest) const
-{
-#ifdef ZMQ_HAVE_WINDOWS_UWP
-    char *buffer = (char *) malloc (1024);
-#else
-    char *buffer = (char *) malloc (IF_MAX_STRING_SIZE);
-#endif
-    alloc_assert (buffer);
-
-    char *if_name_result = NULL;
-
-#if !defined ZMQ_HAVE_WINDOWS_TARGET_XP && !defined ZMQ_HAVE_WINDOWS_UWP
-    if_name_result = if_indextoname (index, buffer);
-#endif
-
-    if (if_name_result == NULL) {
-        free (buffer);
-        return -1;
-    }
-
-    *dest = buffer;
-    return 0;
-}
-
-int zmq::tcp_address_t::wchar_to_utf8 (const WCHAR *src, char **dest) const
-{
-    int rc;
-    int buffer_len =
-      WideCharToMultiByte (CP_UTF8, 0, src, -1, NULL, 0, NULL, 0);
-
-    char *buffer = (char *) malloc (buffer_len);
-    alloc_assert (buffer);
-
-    rc = WideCharToMultiByte (CP_UTF8, 0, src, -1, buffer, buffer_len, NULL, 0);
-
-    if (rc == 0) {
-        free (buffer);
-        return -1;
-    }
-
-    *dest = buffer;
-    return 0;
-}
-
-int zmq::tcp_address_t::resolve_nic_name (const char *nic_,
-                                          bool ipv6_,
-                                          bool is_src_)
-{
-    int rc;
-    bool found = false;
-    const int max_attempts = 10;
-
-    int iterations = 0;
-    IP_ADAPTER_ADDRESSES *addresses = NULL;
-    IP_ADAPTER_ADDRESSES *current_addresses = NULL;
-    unsigned long out_buf_len = sizeof (IP_ADAPTER_ADDRESSES);
-
-    do {
-        addresses = (IP_ADAPTER_ADDRESSES *) malloc (out_buf_len);
-        alloc_assert (addresses);
-
-        rc =
-          GetAdaptersAddresses (AF_UNSPEC,
-                                GAA_FLAG_SKIP_ANYCAST | GAA_FLAG_SKIP_MULTICAST
-                                  | GAA_FLAG_SKIP_DNS_SERVER,
-                                NULL, addresses, &out_buf_len);
-        if (rc == ERROR_BUFFER_OVERFLOW) {
-            free (addresses);
-            addresses = NULL;
-        } else {
-            break;
-        }
-        iterations++;
-    } while ((rc == ERROR_BUFFER_OVERFLOW) && (iterations < max_attempts));
-
-    if (rc == 0) {
-        current_addresses = addresses;
-        while (current_addresses) {
-            char *if_name = NULL;
-            char *if_friendly_name = NULL;
-            int str_rc1, str_rc2;
-
-            str_rc1 = get_interface_name (current_addresses->IfIndex, &if_name);
-            str_rc2 = wchar_to_utf8 (current_addresses->FriendlyName,
-                                     &if_friendly_name);
-
-            //  Find a network adapter by its "name" or "friendly name"
-            if (((str_rc1 == 0) && (!strcmp (nic_, if_name)))
-                || ((str_rc2 == 0) && (!strcmp (nic_, if_friendly_name)))) {
-                //  Iterate over all unicast addresses bound to the current network interface
-                IP_ADAPTER_UNICAST_ADDRESS *unicast_address =
-                  current_addresses->FirstUnicastAddress;
-                IP_ADAPTER_UNICAST_ADDRESS *current_unicast_address =
-                  unicast_address;
-
-                while (current_unicast_address) {
-                    ADDRESS_FAMILY family =
-                      current_unicast_address->Address.lpSockaddr->sa_family;
-
-                    if (family == (ipv6_ ? AF_INET6 : AF_INET)) {
-                        if (is_src_)
-                            memcpy (&source_address,
-                                    current_unicast_address->Address.lpSockaddr,
-                                    (family == AF_INET)
-                                      ? sizeof (struct sockaddr_in)
-                                      : sizeof (struct sockaddr_in6));
-                        else
-                            memcpy (&address,
-                                    current_unicast_address->Address.lpSockaddr,
-                                    (family == AF_INET)
-                                      ? sizeof (struct sockaddr_in)
-                                      : sizeof (struct sockaddr_in6));
-                        found = true;
-                        break;
-                    }
-
-                    current_unicast_address = current_unicast_address->Next;
-                }
-
-                if (found)
-                    break;
-            }
-
-            if (str_rc1 == 0)
-                free (if_name);
-            if (str_rc2 == 0)
-                free (if_friendly_name);
-
-            current_addresses = current_addresses->Next;
-        }
-
-        free (addresses);
-    }
-
-    if (!found) {
-        errno = ENODEV;
-        return -1;
-    }
-    return 0;
-}
-
-#else
-
-//  On other platforms we assume there are no sane interface names.
-int zmq::tcp_address_t::resolve_nic_name (const char *nic_,
-                                          bool ipv6_,
-                                          bool is_src_)
-{
-    LIBZMQ_UNUSED (nic_);
-    LIBZMQ_UNUSED (ipv6_);
-
-    errno = ENODEV;
-    return -1;
-}
-
-#endif
-
-int zmq::tcp_address_t::resolve_interface (const char *interface_,
-                                           bool ipv6_,
-                                           bool is_src_)
-{
-    //  Initialize temporary output pointers with storage address.
-    sockaddr_storage ss;
-    sockaddr *out_addr = (sockaddr *) &ss;
-    size_t out_addrlen;
-
-    //  Initialise IP-format family/port and populate temporary output pointers
-    //  with the address.
-    if (ipv6_) {
-        sockaddr_in6 ip6_addr;
-        memset (&ip6_addr, 0, sizeof (ip6_addr));
-        ip6_addr.sin6_family = AF_INET6;
-#ifdef ZMQ_HAVE_VXWORKS
-        struct in6_addr newaddr = IN6ADDR_ANY_INIT;
-        memcpy (&ip6_addr.sin6_addr, &newaddr, sizeof (in6_addr));
-#else
-        memcpy (&ip6_addr.sin6_addr, &in6addr_any, sizeof (in6addr_any));
-#endif
-        out_addrlen = sizeof (ip6_addr);
-        memcpy (out_addr, &ip6_addr, out_addrlen);
-    } else {
-        sockaddr_in ip4_addr;
-        memset (&ip4_addr, 0, sizeof (ip4_addr));
-        ip4_addr.sin_family = AF_INET;
-        ip4_addr.sin_addr.s_addr = htonl (INADDR_ANY);
-        out_addrlen = sizeof (ip4_addr);
-        memcpy (out_addr, &ip4_addr, out_addrlen);
-    }
-    //  "*" resolves to INADDR_ANY or in6addr_any.
-    if (strcmp (interface_, "*") == 0) {
-        zmq_assert (out_addrlen <= sizeof (address));
-        if (is_src_)
-            memcpy (&source_address, out_addr, out_addrlen);
-        else
-            memcpy (&address, out_addr, out_addrlen);
-        return 0;
-    }
-
-    //  Try to resolve the string as a NIC name.
-    int rc = resolve_nic_name (interface_, ipv6_, is_src_);
-    if (rc == 0 || errno != ENODEV)
-        return rc;
-
-        //  There's no such interface name. Assume literal address.
-#if defined ZMQ_HAVE_OPENVMS && defined __ia64
-    __addrinfo64 *res = NULL;
-    __addrinfo64 req;
-#else
-    addrinfo *res = NULL;
-    addrinfo req;
-#endif
-    memset (&req, 0, sizeof (req));
-
-    //  Choose IPv4 or IPv6 protocol family. Note that IPv6 allows for
-    //  IPv4-in-IPv6 addresses.
-    req.ai_family = ipv6_ ? AF_INET6 : AF_INET;
-
-    //  Arbitrary, not used in the output, but avoids duplicate results.
-    req.ai_socktype = SOCK_STREAM;
-
-    //  Restrict hostname/service to literals to avoid any DNS lookups or
-    //  service-name irregularity due to indeterminate socktype.
-    req.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
-
-#if defined AI_V4MAPPED
-    //  In this API we only require IPv4-mapped addresses when
-    //  no native IPv6 interfaces are available (~AI_ALL).
-    //  This saves an additional DNS roundtrip for IPv4 addresses.
-    if (req.ai_family == AF_INET6)
-        req.ai_flags |= AI_V4MAPPED;
-#endif
-
-    //  Resolve the literal address. Some of the error info is lost in case
-    //  of error, however, there's no way to report EAI errors via errno.
-
-    rc = getaddrinfo (interface_, NULL, &req, &res);
-
-#if defined AI_V4MAPPED
-    // Some OS do have AI_V4MAPPED defined but it is not supported in getaddrinfo()
-    // returning EAI_BADFLAGS. Detect this and retry
-    if (rc == EAI_BADFLAGS && (req.ai_flags & AI_V4MAPPED)) {
-        req.ai_flags &= ~AI_V4MAPPED;
-        rc = getaddrinfo (interface_, NULL, &req, &res);
-    }
-#endif
-
-#if defined ZMQ_HAVE_WINDOWS
-    //  Resolve specific case on Windows platform when using IPv4 address
-    //  with ZMQ_IPv6 socket option.
-    if ((req.ai_family == AF_INET6) && (rc == WSAHOST_NOT_FOUND)) {
-        req.ai_family = AF_INET;
-        rc = getaddrinfo (interface_, NULL, &req, &res);
-    }
-#endif
-
-    if (rc) {
-        errno = ENODEV;
-        return -1;
-    }
-
-    //  Use the first result.
-    zmq_assert (res != NULL);
-    zmq_assert ((size_t) res->ai_addrlen <= sizeof (address));
-    if (is_src_)
-        memcpy (&source_address, res->ai_addr, res->ai_addrlen);
-    else
-        memcpy (&address, res->ai_addr, res->ai_addrlen);
-
-    //  Cleanup getaddrinfo after copying the possibly referenced result.
-    freeaddrinfo (res);
-
-    return 0;
-}
-
-int zmq::tcp_address_t::resolve_hostname (const char *hostname_,
-                                          bool ipv6_,
-                                          bool is_src_)
-{
-//  Set up the query.
-#if defined ZMQ_HAVE_OPENVMS && defined __ia64 && __INITIAL_POINTER_SIZE == 64
-    __addrinfo64 req;
-#else
-    addrinfo req;
-#endif
-    memset (&req, 0, sizeof (req));
-
-    //  Choose IPv4 or IPv6 protocol family. Note that IPv6 allows for
-    //  IPv4-in-IPv6 addresses.
-    req.ai_family = ipv6_ ? AF_INET6 : AF_INET;
-
-    //  Need to choose one to avoid duplicate results from getaddrinfo() - this
-    //  doesn't really matter, since it's not included in the addr-output.
-    req.ai_socktype = SOCK_STREAM;
-
-#if defined AI_V4MAPPED
-    //  In this API we only require IPv4-mapped addresses when
-    //  no native IPv6 interfaces are available.
-    //  This saves an additional DNS roundtrip for IPv4 addresses.
-    if (req.ai_family == AF_INET6)
-        req.ai_flags |= AI_V4MAPPED;
-#endif
-
-        //  Resolve host name. Some of the error info is lost in case of error,
-        //  however, there's no way to report EAI errors via errno.
-#if defined ZMQ_HAVE_OPENVMS && defined __ia64 && __INITIAL_POINTER_SIZE == 64
-    __addrinfo64 *res;
-#else
-    addrinfo *res;
-#endif
-    int rc = getaddrinfo (hostname_, NULL, &req, &res);
-
-#if defined AI_V4MAPPED
-    // Some OS do have AI_V4MAPPED defined but it is not supported in getaddrinfo()
-    // returning EAI_BADFLAGS. Detect this and retry
-    if (rc == EAI_BADFLAGS && (req.ai_flags & AI_V4MAPPED)) {
-        req.ai_flags &= ~AI_V4MAPPED;
-        rc = getaddrinfo (hostname_, NULL, &req, &res);
-    }
-#endif
-
-    if (rc) {
-        switch (rc) {
-            case EAI_MEMORY:
-                errno = ENOMEM;
-                break;
-            default:
-                errno = EINVAL;
-                break;
-        }
-        return -1;
-    }
-
-    //  Copy first result to output addr with hostname and service.
-    zmq_assert ((size_t) res->ai_addrlen <= sizeof (address));
-    if (is_src_)
-        memcpy (&source_address, res->ai_addr, res->ai_addrlen);
-    else
-        memcpy (&address, res->ai_addr, res->ai_addrlen);
-
-    freeaddrinfo (res);
-
-    return 0;
-}
-
 zmq::tcp_address_t::tcp_address_t () : _has_src_addr (false)
 {
     memset (&address, 0, sizeof (address));
@@ -613,106 +72,46 @@ zmq::tcp_address_t::~tcp_address_t ()
 {
 }
 
-int zmq::tcp_address_t::resolve (const char *name_,
-                                 bool local_,
-                                 bool ipv6_,
-                                 bool is_src_)
+int zmq::tcp_address_t::resolve (const char *name_, bool local_, bool ipv6_)
 {
-    if (!is_src_) {
     // Test the ';' to know if we have a source address in name_
     const char *src_delimiter = strrchr (name_, ';');
     if (src_delimiter) {
         std::string src_name (name_, src_delimiter - name_);
-            const int rc = resolve (src_name.c_str (), local_, ipv6_, true);
+
+        ip_resolver_options_t src_resolver_opts;
+
+        src_resolver_opts
+          .bindable (true)
+          //  Restrict hostname/service to literals to avoid any DNS
+          //  lookups or service-name irregularity due to
+          //  indeterminate socktype.
+          .allow_dns (false)
+          .allow_nic_name (true)
+          .ipv6 (ipv6_)
+          .expect_port (true);
+
+        ip_resolver_t src_resolver (src_resolver_opts);
+
+        const int rc =
+          src_resolver.resolve (&source_address, src_name.c_str ());
         if (rc != 0)
             return -1;
         name_ = src_delimiter + 1;
         _has_src_addr = true;
     }
-    }
-
-    //  Find the ':' at end that separates address from the port number.
-    const char *delimiter = strrchr (name_, ':');
-    if (!delimiter) {
-        errno = EINVAL;
-        return -1;
-    }
 
-    //  Separate the address/port.
-    std::string addr_str (name_, delimiter - name_);
-    std::string port_str (delimiter + 1);
-
-    //  Remove square brackets around the address, if any, as used in IPv6
-    if (addr_str.size () >= 2 && addr_str[0] == '['
-        && addr_str[addr_str.size () - 1] == ']')
-        addr_str = addr_str.substr (1, addr_str.size () - 2);
-
-    // Test the '%' to know if we have an interface name / zone_id in the address
-    // Reference: https://tools.ietf.org/html/rfc4007
-    std::size_t pos = addr_str.rfind ('%');
-    uint32_t zone_id = 0;
-    if (pos != std::string::npos) {
-        std::string if_str = addr_str.substr (pos + 1);
-        addr_str = addr_str.substr (0, pos);
-        if (isalpha (if_str.at (0)))
-#if !defined ZMQ_HAVE_WINDOWS_TARGET_XP && !defined ZMQ_HAVE_WINDOWS_UWP       \
-  && !defined ZMQ_HAVE_VXWORKS
-            zone_id = if_nametoindex (if_str.c_str ());
-#else
-            // The function 'if_nametoindex' is not supported on Windows XP.
-            // If we are targeting XP using a vxxx_xp toolset then fail.
-            // This is brutal as this code could be run on later windows clients
-            // meaning the IPv6 zone_id cannot have an interface name.
-            // This could be fixed with a runtime check.
-            zone_id = 0;
-#endif
-        else
-            zone_id = (uint32_t) atoi (if_str.c_str ());
-        if (zone_id == 0) {
-            errno = EINVAL;
-            return -1;
-        }
-    }
+    ip_resolver_options_t resolver_opts;
 
-    //  Allow 0 specifically, to detect invalid port error in atoi if not
-    uint16_t port;
-    if (port_str == "*" || port_str == "0")
-        //  Resolve wildcard to 0 to allow autoselection of port
-        port = 0;
-    else {
-        //  Parse the port number (0 is not a valid port).
-        port = (uint16_t) atoi (port_str.c_str ());
-        if (port == 0) {
-            errno = EINVAL;
-            return -1;
-        }
-    }
+    resolver_opts.bindable (local_)
+      .allow_dns (!local_)
+      .allow_nic_name (local_)
+      .ipv6 (ipv6_)
+      .expect_port (true);
 
-    //  Resolve the IP address.
-    int rc;
-    if (local_ || is_src_)
-        rc = resolve_interface (addr_str.c_str (), ipv6_, is_src_);
-    else
-        rc = resolve_hostname (addr_str.c_str (), ipv6_, is_src_);
-    if (rc != 0)
-        return -1;
-
-    //  Set the port into the address structure.
-    if (is_src_) {
-        if (source_address.generic.sa_family == AF_INET6) {
-            source_address.ipv6.sin6_port = htons (port);
-            source_address.ipv6.sin6_scope_id = zone_id;
-        } else
-            source_address.ipv4.sin_port = htons (port);
-    } else {
-        if (address.generic.sa_family == AF_INET6) {
-            address.ipv6.sin6_port = htons (port);
-            address.ipv6.sin6_scope_id = zone_id;
-        } else
-            address.ipv4.sin_port = htons (port);
-    }
+    ip_resolver_t resolver (resolver_opts);
 
-    return 0;
+    return resolver.resolve (&address, name_);
 }
 
 int zmq::tcp_address_t::to_string (std::string &addr_)
@@ -813,7 +212,17 @@ int zmq::tcp_address_mask_t::resolve (const char *name_, bool ipv6_)
         addr_str.assign (name_);
 
     // Parse address part using standard routines.
-    const int rc = tcp_address_t::resolve_hostname (addr_str.c_str (), ipv6_);
+    ip_resolver_options_t resolver_opts;
+
+    resolver_opts.bindable (false)
+      .allow_dns (false)
+      .allow_nic_name (false)
+      .ipv6 (ipv6_)
+      .expect_port (false);
+
+    ip_resolver_t resolver (resolver_opts);
+
+    const int rc = resolver.resolve (&address, addr_str.c_str ());
     if (rc != 0)
         return rc;
 

src/tcp_address.hpp

@@ -35,6 +35,8 @@
 #include <netinet/in.h>
 #endif
 
+#include "ip_resolver.hpp"
+
 namespace zmq
 {
 class tcp_address_t
@@ -48,8 +50,7 @@ class tcp_address_t
     //  structure. If 'local' is true, names are resolved as local interface
     //  names. If it is false, names are resolved as remote hostnames.
     //  If 'ipv6' is true, the name may resolve to IPv6 address.
-    int
-    resolve (const char *name_, bool local_, bool ipv6_, bool is_src_ = false);
+    int resolve (const char *name_, bool local_, bool ipv6_);
 
     //  The opposite to resolve()
     virtual int to_string (std::string &addr_);
@@ -67,31 +68,8 @@ class tcp_address_t
     bool has_src_addr () const;
 
   protected:
-    int resolve_nic_name (const char *nic_, bool ipv6_, bool is_src_ = false);
-    int resolve_interface (const char *interface_,
-                           bool ipv6_,
-                           bool is_src_ = false);
-    int
-    resolve_hostname (const char *hostname_, bool ipv6_, bool is_src_ = false);
-
-#if defined ZMQ_HAVE_WINDOWS
-    int get_interface_name (unsigned long index, char **dest) const;
-    int wchar_to_utf8 (const WCHAR *src, char **dest) const;
-#endif
-
-    union
-    {
-        sockaddr generic;
-        sockaddr_in ipv4;
-        sockaddr_in6 ipv6;
-    } address;
-
-    union
-    {
-        sockaddr generic;
-        sockaddr_in ipv4;
-        sockaddr_in6 ipv6;
-    } source_address;
+    ip_addr_t address;
+    ip_addr_t source_address;
     bool _has_src_addr;
 };
 

tests/testutil.hpp

@@ -80,6 +80,8 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <net/if.h>
+#include <netdb.h>
 #if defined(ZMQ_HAVE_AIX)
 #include <sys/types.h>
 #include <sys/socketvar.h>
@@ -412,6 +414,34 @@ int is_tipc_available (void)
 #endif // ZMQ_HAVE_TIPC
 }
 
+//  Wrapper around 'inet_pton' for systems that don't support it (e.g. Windows
+//  XP)
+int test_inet_pton (int af_, const char *src_, void *dst_)
+{
+#if defined(ZMQ_HAVE_WINDOWS) && (_WIN32_WINNT < 0x0600)
+    if (af_ == AF_INET) {
+        struct in_addr *ip4addr = (struct in_addr *) dst_;
+
+        ip4addr->s_addr = inet_addr (src_);
+
+        //  INADDR_NONE is -1 which is also a valid representation for IP
+        //  255.255.255.255
+        if (ip4addr->s_addr == INADDR_NONE
+            && strcmp (src_, "255.255.255.255") != 0) {
+            return 0;
+        }
+
+        //  Success
+        return 1;
+    } else {
+        //  Not supported.
+        return 0;
+    }
+#else
+    return inet_pton (af_, src_, dst_);
+#endif
+}
+
 #if defined(ZMQ_HAVE_WINDOWS)
 
 int close (int fd)

unittests/CMakeLists.txt

@@ -5,6 +5,7 @@ set(unittests
   unittest_ypipe
   unittest_poller
   unittest_mtrie
+  unittest_ip_resolver
 )
 
 #IF (ENABLE_DRAFTS)

unittests/unittest_ip_resolver.cpp

+/*
+Copyright (c) 2018 Contributors as noted in the AUTHORS file
+
+This file is part of 0MQ.
+
+0MQ is free software; you can redistribute it and/or modify it under
+the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 3 of the License, or
+(at your option) any later version.
+
+0MQ is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <unity.h>
+#include "../tests/testutil.hpp"
+
+#include <ip_resolver.hpp>
+#include <ip.hpp>
+
+void setUp ()
+{
+}
+
+void tearDown ()
+{
+}
+
+class test_ip_resolver_t : public zmq::ip_resolver_t
+{
+  public:
+    test_ip_resolver_t (zmq::ip_resolver_options_t opts_) :
+        ip_resolver_t (opts_)
+    {
+    }
+
+  protected:
+    struct dns_lut_t
+    {
+        const char *hostname;
+        const char *ipv4;
+        const char *ipv6;
+    };
+
+    virtual int do_getaddrinfo (const char *node_,
+                                const char *service_,
+                                const struct addrinfo *hints_,
+                                struct addrinfo **res_)
+    {
+        static const struct dns_lut_t dns_lut[] = {
+          {"ip.zeromq.org", "10.100.0.1", "fdf5:d058:d656::1"},
+          {"ipv4only.zeromq.org", "10.100.0.2", "::ffff:10.100.0.2"},
+          {"ipv6only.zeromq.org", NULL, "fdf5:d058:d656::2"},
+        };
+        unsigned lut_len = sizeof (dns_lut) / sizeof (dns_lut[0]);
+        struct addrinfo ai;
+
+        assert (service_ == NULL);
+
+        bool ipv6 = (hints_->ai_family == AF_INET6);
+        bool no_dns = hints_->ai_flags & AI_NUMERICHOST;
+        const char *ip = NULL;
+
+        if (!no_dns) {
+            for (unsigned i = 0; i < lut_len; i++) {
+                if (strcmp (dns_lut[i].hostname, node_) == 0) {
+                    if (ipv6) {
+                        ip = dns_lut[i].ipv6;
+                    } else {
+                        ip = dns_lut[i].ipv4;
+
+                        if (ip == NULL) {
+                            //  No address associated with NAME
+                            return EAI_NODATA;
+                        }
+                    }
+                }
+            }
+        }
+
+        if (ip == NULL) {
+            //  No entry for 'node_' found in the LUT (or DNS is
+            //  forbidden), assume that it's a numeric IP address
+            ip = node_;
+        }
+
+        //  Call the real getaddrinfo implementation, making sure that it won't
+        //  attempt to resolve using DNS
+        ai = *hints_;
+        ai.ai_flags |= AI_NUMERICHOST;
+
+        return zmq::ip_resolver_t::do_getaddrinfo (ip, NULL, &ai, res_);
+    }
+
+    virtual unsigned int do_if_nametoindex (const char *ifname_)
+    {
+        static const char *dummy_interfaces[] = {
+          "lo0",
+          "eth0",
+          "eth1",
+        };
+        unsigned lut_len =
+          sizeof (dummy_interfaces) / sizeof (dummy_interfaces[0]);
+
+        for (unsigned i = 0; i < lut_len; i++) {
+            if (strcmp (dummy_interfaces[i], ifname_) == 0) {
+                //  The dummy index will be the position in the array + 1 (0 is
+                //  invalid)
+                return i + 1;
+            }
+        }
+
+        //  Not found
+        return 0;
+    }
+};
+
+//  Attempt a resolution and test the results. If 'expected_addr_' is NULL
+//  assume that the resolution is meant to fail.
+//
+//  On windows we can receive an IPv4 address even when an IPv6 is requested, if
+//  we're in this situation then we compare to 'expected_addr_v4_failover_'
+//  instead.
+static void test_resolve (zmq::ip_resolver_options_t opts_,
+                          const char *name_,
+                          const char *expected_addr_,
+                          uint16_t expected_port_ = 0,
+                          uint16_t expected_zone_ = 0,
+                          const char *expected_addr_v4_failover_ = NULL)
+{
+    zmq::ip_addr_t addr;
+    int family = opts_.ipv6 () ? AF_INET6 : AF_INET;
+
+    if (family == AF_INET6 && !is_ipv6_available ()) {
+        TEST_IGNORE_MESSAGE ("ipv6 is not available");
+    }
+
+    //  Generate an invalid but well-defined 'ip_addr_t'. Avoids testing
+    //  uninitialized values if the code is buggy.
+    memset (&addr, 0xba, sizeof (addr));
+
+    test_ip_resolver_t resolver (opts_);
+
+    int rc = resolver.resolve (&addr, name_);
+
+    if (expected_addr_ == NULL) {
+        TEST_ASSERT_EQUAL (-1, rc);
+        return;
+    } else {
+        TEST_ASSERT_EQUAL (0, rc);
+    }
+
+#if defined ZMQ_HAVE_WINDOWS
+    if (family == AF_INET6 && expected_addr_v4_failover_ != NULL &&
+        addr.generic.sa_family == AF_INET) {
+        //  We've requested an IPv6 but the system gave us an IPv4, use the
+        //  failover address
+        family = AF_INET;
+        expected_addr_ = expected_addr_v4_failover_;
+    }
+#else
+    (void)expected_addr_v4_failover_;
+#endif
+
+    TEST_ASSERT_EQUAL (family, addr.generic.sa_family);
+
+    if (family == AF_INET6) {
+        struct in6_addr expected_addr;
+        const sockaddr_in6 *ip6_addr = &addr.ipv6;
+
+        assert (test_inet_pton (AF_INET6, expected_addr_, &expected_addr) == 1);
+
+        int neq = memcmp (&ip6_addr->sin6_addr, &expected_addr,
+                          sizeof (expected_addr_));
+
+        TEST_ASSERT_EQUAL (0, neq);
+        TEST_ASSERT_EQUAL (htons (expected_port_), ip6_addr->sin6_port);
+        TEST_ASSERT_EQUAL (expected_zone_, ip6_addr->sin6_scope_id);
+    } else {
+        struct in_addr expected_addr;
+        const sockaddr_in *ip4_addr = &addr.ipv4;
+
+        assert (test_inet_pton (AF_INET, expected_addr_, &expected_addr) == 1);
+
+        TEST_ASSERT_EQUAL (AF_INET, addr.generic.sa_family);
+        TEST_ASSERT_EQUAL (expected_addr.s_addr, ip4_addr->sin_addr.s_addr);
+        TEST_ASSERT_EQUAL (htons (expected_port_), ip4_addr->sin_port);
+    }
+}
+
+// Helper macro to define the v4/v6 function pairs
+#define MAKE_TEST_V4V6(_test)                                                  \
+    static void _test##_ipv4 () { _test (false); }                             \
+                                                                               \
+    static void _test##_ipv6 () { _test (true); }
+
+static void test_bind_any (int ipv6_)
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.bindable (true).expect_port (true).ipv6 (ipv6_);
+
+    const char *expected = ipv6_ ? "::" : "0.0.0.0";
+    test_resolve (resolver_opts, "*:*", expected, 0);
+}
+MAKE_TEST_V4V6 (test_bind_any)
+
+static void test_nobind_any (int ipv6_)
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true).ipv6 (ipv6_);
+
+    //  Wildcard should be rejected if we're not looking for a
+    //  bindable address
+    test_resolve (resolver_opts, "*:*", NULL);
+}
+MAKE_TEST_V4V6 (test_nobind_any)
+
+static void test_nobind_any_port (int ipv6_)
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true).ipv6 (ipv6_);
+
+    //  Wildcard should be rejected if we're not looking for a
+    //  bindable address
+    test_resolve (resolver_opts, "*:1234", NULL);
+}
+MAKE_TEST_V4V6 (test_nobind_any_port)
+
+static void test_nobind_addr_anyport (int ipv6_)
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true).ipv6 (ipv6_);
+
+    // This however works. Should it ? For the time being I'm going to
+    // keep it that way for backcompat but I can't imagine why you'd
+    // want a wildcard port if you're not binding.
+    const char *expected = ipv6_ ? "::ffff:127.0.0.1" : "127.0.0.1";
+    const char *fallback = ipv6_ ? "127.0.0.1" : NULL;
+    test_resolve (resolver_opts, "127.0.0.1:*", expected, 0, 0, fallback);
+}
+MAKE_TEST_V4V6 (test_nobind_addr_anyport)
+
+static void test_parse_ipv4_simple ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    test_resolve (resolver_opts, "1.2.128.129", "1.2.128.129");
+}
+
+static void test_parse_ipv4_zero ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    test_resolve (resolver_opts, "0.0.0.0", "0.0.0.0");
+}
+
+static void test_parse_ipv4_max ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    test_resolve (resolver_opts, "255.255.255.255", "255.255.255.255");
+}
+
+static void test_parse_ipv4_brackets ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    //  Not particularly useful, but valid
+    test_resolve (resolver_opts, "[1.2.128.129]", "1.2.128.129");
+}
+
+static void test_parse_ipv4_brackets_missingl ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    test_resolve (resolver_opts, "1.2.128.129]", NULL);
+}
+
+static void test_parse_ipv4_brackets_missingr ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    test_resolve (resolver_opts, "[1.2.128.129", NULL);
+}
+
+static void test_parse_ipv4_brackets_bad ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    test_resolve (resolver_opts, "[1.2.128].129", NULL);
+}
+
+static void test_parse_ipv4_reject_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    //  No port expected, should be rejected
+    test_resolve (resolver_opts, "1.2.128.129:123", NULL);
+}
+
+static void test_parse_ipv4_reject_any ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    //  No port expected, should be rejected
+    test_resolve (resolver_opts, "1.2.128.129:*", NULL);
+}
+
+static void test_parse_ipv4_reject_ipv6 ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    //  No port expected, should be rejected
+    test_resolve (resolver_opts, "::1", NULL);
+}
+
+static void test_parse_ipv4_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    test_resolve (resolver_opts, "1.2.128.129:123", "1.2.128.129", 123);
+}
+
+static void test_parse_ipv4_port0 ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    //  Port 0 is accepted and is equivalent to *
+    test_resolve (resolver_opts, "1.2.128.129:0", "1.2.128.129", 0);
+}
+
+static void test_parse_ipv4_port_garbage ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    //  The code doesn't validate that the port doesn't contain garbage
+    test_resolve (resolver_opts, "1.2.3.4:567bad", "1.2.3.4", 567);
+}
+
+static void test_parse_ipv4_port_missing ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    test_resolve (resolver_opts, "1.2.3.4", NULL);
+}
+
+static void test_parse_ipv4_port_bad ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    test_resolve (resolver_opts, "1.2.3.4:bad", NULL);
+}
+
+static void test_parse_ipv4_port_brackets ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    test_resolve (resolver_opts, "[192.168.1.1]:5555", "192.168.1.1", 5555);
+}
+
+static void test_parse_ipv4_port_brackets_bad ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    test_resolve (resolver_opts, "[192.168.1.1:]5555", NULL);
+}
+
+static void test_parse_ipv4_port_brackets_bad2 ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    test_resolve (resolver_opts, "[192.168.1.1:5555]", NULL);
+}
+
+static void test_parse_ipv4_wild_brackets_bad ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    test_resolve (resolver_opts, "[192.168.1.1:*]", NULL);
+}
+
+static void test_parse_ipv4_port_ipv6_reject ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true);
+
+    test_resolve (resolver_opts, "[::1]:1234", NULL);
+}
+
+static void test_parse_ipv6_simple ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "::1", "::1");
+}
+
+static void test_parse_ipv6_simple2 ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "abcd:1234::1:0:234", "abcd:1234::1:0:234");
+}
+
+static void test_parse_ipv6_zero ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "::", "::");
+}
+
+static void test_parse_ipv6_max ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff",
+                  "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff");
+}
+
+static void test_parse_ipv6_brackets ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "[::1]", "::1");
+}
+
+static void test_parse_ipv6_brackets_missingl ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "::1]", NULL);
+}
+
+static void test_parse_ipv6_brackets_missingr ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "[::1", NULL);
+}
+
+static void test_parse_ipv6_brackets_bad ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "[abcd:1234::1:]0:234", NULL);
+}
+
+static void test_parse_ipv6_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).expect_port (true);
+
+    test_resolve (resolver_opts, "[1234::1]:80", "1234::1", 80);
+}
+
+static void test_parse_ipv6_port_any ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).expect_port (true);
+
+    test_resolve (resolver_opts, "[1234::1]:*", "1234::1", 0);
+}
+
+static void test_parse_ipv6_port_nobrackets ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).expect_port (true);
+
+    //  Should this be allowed? Seems error-prone but so far ZMQ accepts it.
+    test_resolve (resolver_opts, "abcd:1234::1:0:234:123", "abcd:1234::1:0:234",
+                  123);
+}
+
+static void test_parse_ipv4_in_ipv6 ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    //  Parsing IPv4 should also work if an IPv6 is requested, it returns an
+    //  IPv6 with the IPv4 address embedded (except sometimes on Windows where
+    //  we end up with an IPv4 anyway)
+    test_resolve (resolver_opts, "11.22.33.44", "::ffff:11.22.33.44", 0, 0,
+                  "11.22.33.44");
+}
+
+static void test_parse_ipv4_in_ipv6_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).expect_port (true);
+
+    test_resolve (resolver_opts, "11.22.33.44:55", "::ffff:11.22.33.44", 55, 0,
+                  "11.22.33.44");
+}
+
+static void test_parse_ipv6_scope_int ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "3000:4:5::1:234%2", "3000:4:5::1:234", 0, 2);
+}
+
+static void test_parse_ipv6_scope_zero ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "3000:4:5::1:234%0", NULL);
+}
+
+static void test_parse_ipv6_scope_int_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true).ipv6 (true);
+
+    test_resolve (resolver_opts, "3000:4:5::1:234%2:1111", "3000:4:5::1:234",
+                  1111, 2);
+}
+
+static void test_parse_ipv6_scope_if ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "3000:4:5::1:234%eth1", "3000:4:5::1:234", 0,
+                  3);
+}
+
+static void test_parse_ipv6_scope_if_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true).ipv6 (true);
+
+    test_resolve (resolver_opts, "3000:4:5::1:234%eth0:8080", "3000:4:5::1:234",
+                  8080, 2);
+}
+
+static void test_parse_ipv6_scope_if_port_brackets ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true).ipv6 (true);
+
+    test_resolve (resolver_opts, "[3000:4:5::1:234%eth0]:8080",
+                  "3000:4:5::1:234", 8080, 2);
+}
+
+static void test_parse_ipv6_scope_badif ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true);
+
+    test_resolve (resolver_opts, "3000:4:5::1:234%bad0", NULL);
+}
+
+static void test_dns_ipv4_simple ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    test_resolve (resolver_opts, "ip.zeromq.org", "10.100.0.1");
+}
+
+static void test_dns_ipv4_only ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    test_resolve (resolver_opts, "ipv4only.zeromq.org", "10.100.0.2");
+}
+
+static void test_dns_ipv4_invalid ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    test_resolve (resolver_opts, "invalid.zeromq.org", NULL);
+}
+
+static void test_dns_ipv4_ipv6 ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    test_resolve (resolver_opts, "ipv6only.zeromq.org", NULL);
+}
+
+static void test_dns_ipv4_numeric ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    //  Numeric IPs should still work
+    test_resolve (resolver_opts, "5.4.3.2", "5.4.3.2");
+}
+
+static void test_dns_ipv4_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.expect_port (true).allow_dns (true);
+
+    test_resolve (resolver_opts, "ip.zeromq.org:1234", "10.100.0.1", 1234);
+}
+
+static void test_dns_ipv6_simple ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).allow_dns (true);
+
+    test_resolve (resolver_opts, "ip.zeromq.org", "fdf5:d058:d656::1");
+}
+
+static void test_dns_ipv6_only ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).allow_dns (true);
+
+    test_resolve (resolver_opts, "ipv6only.zeromq.org", "fdf5:d058:d656::2");
+}
+
+static void test_dns_ipv6_invalid ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).allow_dns (true);
+
+    test_resolve (resolver_opts, "invalid.zeromq.org", NULL);
+}
+
+static void test_dns_ipv6_ipv4 ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).allow_dns (true);
+
+    //  If a host doesn't have an IPv6 then it should resolve as an embedded v4
+    //  address in an IPv6
+    test_resolve (resolver_opts, "ipv4only.zeromq.org", "::ffff:10.100.0.2");
+}
+
+static void test_dns_ipv6_numeric ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).allow_dns (true);
+
+    //  Numeric IPs should still work
+    test_resolve (resolver_opts, "fdf5:d058:d656::1", "fdf5:d058:d656::1");
+}
+
+static void test_dns_ipv6_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.ipv6 (true).expect_port (true).allow_dns (true);
+
+    test_resolve (resolver_opts, "ip.zeromq.org:1234", "fdf5:d058:d656::1",
+                  1234);
+}
+
+void test_dns_brackets ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    test_resolve (resolver_opts, "[ip.zeromq.org]", "10.100.0.1");
+}
+
+void test_dns_brackets_bad ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    test_resolve (resolver_opts, "[ip.zeromq].org", NULL);
+}
+
+void test_dns_brackets_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    test_resolve (resolver_opts, "[ip.zeromq.org]:22", "10.100.0.1", 22);
+}
+
+void test_dns_brackets_port_bad ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true);
+
+    test_resolve (resolver_opts, "[ip.zeromq.org:22]", NULL);
+}
+
+void test_dns_deny (int ipv6_)
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (false).ipv6 (ipv6_);
+
+    //  DNS resolution shouldn't work when disallowed
+    test_resolve (resolver_opts, "ip.zeromq.org", NULL);
+}
+MAKE_TEST_V4V6 (test_dns_deny)
+
+void test_dns_ipv6_scope ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true).ipv6 (true);
+
+    //  Not sure if that's very useful but you could technically add a scope
+    //  identifier to a hostname
+    test_resolve (resolver_opts, "ip.zeromq.org%lo0", "fdf5:d058:d656::1", 0,
+                  1);
+}
+
+void test_dns_ipv6_scope_port ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true).expect_port (true).ipv6 (true);
+
+    //  Not sure if that's very useful but you could technically add a scope
+    //  identifier to a hostname
+    test_resolve (resolver_opts, "ip.zeromq.org%lo0:4444", "fdf5:d058:d656::1",
+                  4444, 1);
+}
+
+void test_dns_ipv6_scope_port_brackets ()
+{
+    zmq::ip_resolver_options_t resolver_opts;
+
+    resolver_opts.allow_dns (true).expect_port (true).ipv6 (true);
+
+    test_resolve (resolver_opts, "[ip.zeromq.org%lo0]:4444",
+                  "fdf5:d058:d656::1", 4444, 1);
+}
+
+int main (void)
+{
+    zmq::initialize_network ();
+    setup_test_environment ();
+
+    UNITY_BEGIN ();
+
+    RUN_TEST (test_bind_any_ipv4);
+    RUN_TEST (test_bind_any_ipv6);
+    RUN_TEST (test_nobind_any_ipv4);
+    RUN_TEST (test_nobind_any_ipv6);
+    RUN_TEST (test_nobind_any_port_ipv4);
+    RUN_TEST (test_nobind_any_port_ipv6);
+    RUN_TEST (test_nobind_addr_anyport_ipv4);
+    RUN_TEST (test_nobind_addr_anyport_ipv6);
+    RUN_TEST (test_parse_ipv4_simple);
+    RUN_TEST (test_parse_ipv4_zero);
+    RUN_TEST (test_parse_ipv4_max);
+    RUN_TEST (test_parse_ipv4_brackets);
+    RUN_TEST (test_parse_ipv4_brackets_missingl);
+    RUN_TEST (test_parse_ipv4_brackets_missingr);
+    RUN_TEST (test_parse_ipv4_brackets_bad);
+    RUN_TEST (test_parse_ipv4_reject_port);
+    RUN_TEST (test_parse_ipv4_reject_any);
+    RUN_TEST (test_parse_ipv4_reject_ipv6);
+    RUN_TEST (test_parse_ipv4_port);
+    RUN_TEST (test_parse_ipv4_port0);
+    RUN_TEST (test_parse_ipv4_port_garbage);
+    RUN_TEST (test_parse_ipv4_port_missing);
+    RUN_TEST (test_parse_ipv4_port_bad);
+    RUN_TEST (test_parse_ipv4_port_brackets);
+    RUN_TEST (test_parse_ipv4_port_brackets_bad);
+    RUN_TEST (test_parse_ipv4_port_brackets_bad2);
+    RUN_TEST (test_parse_ipv4_wild_brackets_bad);
+    RUN_TEST (test_parse_ipv4_port_ipv6_reject);
+    RUN_TEST (test_parse_ipv6_simple);
+    RUN_TEST (test_parse_ipv6_simple2);
+    RUN_TEST (test_parse_ipv6_zero);
+    RUN_TEST (test_parse_ipv6_max);
+    RUN_TEST (test_parse_ipv6_brackets);
+    RUN_TEST (test_parse_ipv6_brackets_missingl);
+    RUN_TEST (test_parse_ipv6_brackets_missingr);
+    RUN_TEST (test_parse_ipv6_brackets_bad);
+    RUN_TEST (test_parse_ipv6_port);
+    RUN_TEST (test_parse_ipv6_port_any);
+    RUN_TEST (test_parse_ipv6_port_nobrackets);
+    RUN_TEST (test_parse_ipv4_in_ipv6);
+    RUN_TEST (test_parse_ipv4_in_ipv6_port);
+    RUN_TEST (test_parse_ipv6_scope_int);
+    RUN_TEST (test_parse_ipv6_scope_zero);
+    RUN_TEST (test_parse_ipv6_scope_int_port);
+    RUN_TEST (test_parse_ipv6_scope_if);
+    RUN_TEST (test_parse_ipv6_scope_if_port);
+    RUN_TEST (test_parse_ipv6_scope_if_port_brackets);
+    RUN_TEST (test_parse_ipv6_scope_badif);
+    RUN_TEST (test_dns_ipv4_simple);
+    RUN_TEST (test_dns_ipv4_only);
+    RUN_TEST (test_dns_ipv4_invalid);
+    RUN_TEST (test_dns_ipv4_ipv6);
+    RUN_TEST (test_dns_ipv4_numeric);
+    RUN_TEST (test_dns_ipv4_port);
+    RUN_TEST (test_dns_ipv6_simple);
+    RUN_TEST (test_dns_ipv6_only);
+    RUN_TEST (test_dns_ipv6_invalid);
+    RUN_TEST (test_dns_ipv6_ipv4);
+    RUN_TEST (test_dns_ipv6_numeric);
+    RUN_TEST (test_dns_ipv6_port);
+    RUN_TEST (test_dns_brackets);
+    RUN_TEST (test_dns_brackets_bad);
+    RUN_TEST (test_dns_deny_ipv4);
+    RUN_TEST (test_dns_deny_ipv6);
+    RUN_TEST (test_dns_ipv6_scope);
+    RUN_TEST (test_dns_ipv6_scope_port);
+    RUN_TEST (test_dns_ipv6_scope_port_brackets);
+
+    zmq::shutdown_network ();
+
+    return UNITY_END ();
+}