options.cpp

/*
    Copyright (c) 2007-2015 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/>.
*/

#include <string.h>

#include "options.hpp"
#include "err.hpp"
#include "../include/zmq_utils.h"

zmq::options_t::options_t () :
    sndhwm (1000),
    rcvhwm (1000),
    affinity (0),
    identity_size (0),
    rate (100),
    recovery_ivl (10000),
    multicast_hops (1),
    multicast_maxtpdu (1500),
    sndbuf (-1),
    rcvbuf (-1),
    tos (0),
    type (-1),
    linger (-1),
    connect_timeout (0),
    tcp_retransmit_timeout (0),
    reconnect_ivl (100),
    reconnect_ivl_max (0),
    backlog (100),
    maxmsgsize (-1),
    rcvtimeo (-1),
    sndtimeo (-1),
    ipv6 (0),
    immediate (0),
    filter (false),
    invert_matching(false),
    recv_identity (false),
    raw_socket (false),
    raw_notify (true),
    tcp_keepalive (-1),
    tcp_keepalive_cnt (-1),
    tcp_keepalive_idle (-1),
    tcp_keepalive_intvl (-1),
    tcp_recv_buffer_size (8192),
    tcp_send_buffer_size (8192),
    mechanism (ZMQ_NULL),
    as_server (0),
    gss_plaintext (false),
    socket_id (0),
    conflate (false),
    handshake_ivl (30000),
    connected (false),
    heartbeat_ttl (0),
    heartbeat_interval (0),
    heartbeat_timeout (-1)
{
#if defined ZMQ_HAVE_VMCI
    vmci_buffer_size = 0;
    vmci_buffer_min_size = 0;
    vmci_buffer_max_size = 0;
    vmci_connect_timeout = -1;
#endif
}

int zmq::options_t::setsockopt (int option_, const void *optval_,
    size_t optvallen_)
{
    bool is_int = (optvallen_ == sizeof (int));
    int value = is_int? *((int *) optval_): 0;
#if defined (ZMQ_ACT_MILITANT)
    bool malformed = true;          //  Did caller pass a bad option value?
#endif

    switch (option_) {
        case ZMQ_SNDHWM:
            if (is_int && value >= 0) {
                sndhwm = value;
                return 0;
            }
            break;

        case ZMQ_RCVHWM:
            if (is_int && value >= 0) {
                rcvhwm = value;
                return 0;
            }
            break;

        case ZMQ_AFFINITY:
            if (optvallen_ == sizeof (uint64_t)) {
                affinity = *((uint64_t*) optval_);
                return 0;
            }
            break;

        case ZMQ_IDENTITY:
            //  Identity is any binary string from 1 to 255 octets
            if (optvallen_ > 0 && optvallen_ < 256) {
                identity_size = (unsigned char) optvallen_;
                memcpy (identity, optval_, identity_size);
                return 0;
            }
            break;

        case ZMQ_RATE:
            if (is_int && value > 0) {
                rate = value;
                return 0;
            }
            break;

        case ZMQ_RECOVERY_IVL:
            if (is_int && value >= 0) {
                recovery_ivl = value;
                return 0;
            }
            break;

        case ZMQ_SNDBUF:
            if (is_int && value >= 0) {
                sndbuf = value;
                return 0;
            }
            break;

        case ZMQ_RCVBUF:
            if (is_int && value >= 0) {
                rcvbuf = value;
                return 0;
            }
            break;

        case ZMQ_TOS:
            if (is_int && value >= 0) {
                tos = value;
                return 0;
            }
            break;

        case ZMQ_LINGER:
            if (is_int && value >= -1) {
                linger = value;
                return 0;
            }
            break;

        case ZMQ_CONNECT_TIMEOUT:
            if (is_int && value >= 0) {
                connect_timeout = value;
                return 0;
            }
            break;

        case ZMQ_TCP_RETRANSMIT_TIMEOUT:
            if (is_int && value >= 0) {
                tcp_retransmit_timeout = value;
                return 0;
            }
            break;

        case ZMQ_RECONNECT_IVL:
            if (is_int && value >= -1) {
                reconnect_ivl = value;
                return 0;
            }
            break;

        case ZMQ_RECONNECT_IVL_MAX:
            if (is_int && value >= 0) {
                reconnect_ivl_max = value;
                return 0;
            }
            break;

        case ZMQ_BACKLOG:
            if (is_int && value >= 0) {
                backlog = value;
                return 0;
            }
            break;

        case ZMQ_MAXMSGSIZE:
            if (optvallen_ == sizeof (int64_t)) {
                maxmsgsize = *((int64_t *) optval_);
                return 0;
            }
            break;

        case ZMQ_MULTICAST_HOPS:
            if (is_int && value > 0) {
                multicast_hops = value;
                return 0;
            }
            break;

        case ZMQ_MULTICAST_MAXTPDU:
            if (is_int && value > 0) {
                multicast_maxtpdu = value;
                return 0;
            }
            break;

        case ZMQ_RCVTIMEO:
            if (is_int && value >= -1) {
                rcvtimeo = value;
                return 0;
            }
            break;

        case ZMQ_SNDTIMEO:
            if (is_int && value >= -1) {
                sndtimeo = value;
                return 0;
            }
            break;

        /*  Deprecated in favor of ZMQ_IPV6  */
        case ZMQ_IPV4ONLY:
            if (is_int && (value == 0 || value == 1)) {
                ipv6 = (value == 0);
                return 0;
            }
            break;

        /*  To replace the somewhat surprising IPV4ONLY */
        case ZMQ_IPV6:
            if (is_int && (value == 0 || value == 1)) {
                ipv6 = (value != 0);
                return 0;
            }
            break;

        case ZMQ_SOCKS_PROXY:
            if (optval_ == NULL && optvallen_ == 0) {
                socks_proxy_address.clear ();
                return 0;
            }
            else
            if (optval_ != NULL && optvallen_ > 0 ) {
                socks_proxy_address =
                    std::string ((const char *) optval_, optvallen_);
                return 0;
            }
            break;

        case ZMQ_TCP_KEEPALIVE:
            if (is_int && (value == -1 || value == 0 || value == 1)) {
                tcp_keepalive = value;
                return 0;
            }
            break;

        case ZMQ_TCP_KEEPALIVE_CNT:
            if (is_int && (value == -1 || value >= 0)) {
                tcp_keepalive_cnt = value;
                return 0;
            }
            break;

        case ZMQ_TCP_KEEPALIVE_IDLE:
            if (is_int && (value == -1 || value >= 0)) {
                tcp_keepalive_idle = value;
                return 0;
            }
            break;

        case ZMQ_TCP_KEEPALIVE_INTVL:
            if (is_int && (value == -1 || value >= 0)) {
                tcp_keepalive_intvl = value;
                return 0;
            }
            break;

        case ZMQ_TCP_RECV_BUFFER:
            if (is_int && (value > 0) ) {
                tcp_recv_buffer_size = static_cast<unsigned int>(value);
                return 0;
            }
            break;

        case ZMQ_TCP_SEND_BUFFER:
            if (is_int && (value > 0) ) {
                tcp_send_buffer_size = static_cast<unsigned int>(value);
                return 0;
            }
            break;

        case ZMQ_IMMEDIATE:
            if (is_int && (value == 0 || value == 1)) {
                immediate = value;
                return 0;
            }
            break;

        case ZMQ_TCP_ACCEPT_FILTER:
            if (optvallen_ == 0 && optval_ == NULL) {
                tcp_accept_filters.clear ();
                return 0;
            }
            else
            if (optvallen_ > 0 && optvallen_ < 256 && optval_ != NULL && *((const char*) optval_) != 0) {
                std::string filter_str ((const char *) optval_, optvallen_);
                tcp_address_mask_t mask;
                int rc = mask.resolve (filter_str.c_str (), ipv6);
                if (rc == 0) {
                    tcp_accept_filters.push_back (mask);
                    return 0;
                }
            }
            break;

#       if defined ZMQ_HAVE_SO_PEERCRED || defined ZMQ_HAVE_LOCAL_PEERCRED
        case ZMQ_IPC_FILTER_UID:
            if (optvallen_ == 0 && optval_ == NULL) {
                ipc_uid_accept_filters.clear ();
                return 0;
            }
            else
            if (optvallen_ == sizeof (uid_t) && optval_ != NULL) {
                ipc_uid_accept_filters.insert (*((uid_t *) optval_));
                return 0;
            }
            break;

        case ZMQ_IPC_FILTER_GID:
            if (optvallen_ == 0 && optval_ == NULL) {
                ipc_gid_accept_filters.clear ();
                return 0;
            }
            else
            if (optvallen_ == sizeof (gid_t) && optval_ != NULL) {
                ipc_gid_accept_filters.insert (*((gid_t *) optval_));
                return 0;
            }
            break;
#       endif

#       if defined ZMQ_HAVE_SO_PEERCRED
        case ZMQ_IPC_FILTER_PID:
            if (optvallen_ == 0 && optval_ == NULL) {
                ipc_pid_accept_filters.clear ();
                return 0;
            }
            else
            if (optvallen_ == sizeof (pid_t) && optval_ != NULL) {
                ipc_pid_accept_filters.insert (*((pid_t *) optval_));
                return 0;
            }
            break;
#       endif

        case ZMQ_PLAIN_SERVER:
            if (is_int && (value == 0 || value == 1)) {
                as_server = value;
                mechanism = value? ZMQ_PLAIN: ZMQ_NULL;
                return 0;
            }
            break;

        case ZMQ_PLAIN_USERNAME:
            if (optvallen_ == 0 && optval_ == NULL) {
                mechanism = ZMQ_NULL;
                return 0;
            }
            else
            if (optvallen_ > 0 && optvallen_ < 256 && optval_ != NULL) {
                plain_username.assign ((const char *) optval_, optvallen_);
                as_server = 0;
                mechanism = ZMQ_PLAIN;
                return 0;
            }
            break;

        case ZMQ_PLAIN_PASSWORD:
            if (optvallen_ == 0 && optval_ == NULL) {
                mechanism = ZMQ_NULL;
                return 0;
            }
            else
            if (optvallen_ > 0 && optvallen_ < 256 && optval_ != NULL) {
                plain_password.assign ((const char *) optval_, optvallen_);
                as_server = 0;
                mechanism = ZMQ_PLAIN;
                return 0;
            }
            break;

        case ZMQ_ZAP_DOMAIN:
            if (optvallen_ < 256) {
                zap_domain.assign ((const char *) optval_, optvallen_);
                return 0;
            }
            break;

        //  If libsodium isn't installed, these options provoke EINVAL
#       ifdef HAVE_LIBSODIUM
        case ZMQ_CURVE_SERVER:
            if (is_int && (value == 0 || value == 1)) {
                as_server = value;
                mechanism = value? ZMQ_CURVE: ZMQ_NULL;
                return 0;
            }
            break;

        case ZMQ_CURVE_PUBLICKEY:
            //  TODO: refactor repeated code for these three options
            //  into set_curve_key (destination, optval, optlen) method
            //  ==> set_curve_key (curve_public_key, optval_, optvallen_);
            if (optvallen_ == CURVE_KEYSIZE) {
                memcpy (curve_public_key, optval_, CURVE_KEYSIZE);
                mechanism = ZMQ_CURVE;
                return 0;
            }
            else
            if (optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                if (zmq_z85_decode (curve_public_key, (char *) optval_)) {
                    mechanism = ZMQ_CURVE;
                    return 0;
                }
            }
            else
            //  Deprecated, not symmetrical with zmq_getsockopt
            if (optvallen_ == CURVE_KEYSIZE_Z85) {
                char z85_key [CURVE_KEYSIZE_Z85 + 1];
                memcpy (z85_key, (char *) optval_, CURVE_KEYSIZE_Z85);
                z85_key [CURVE_KEYSIZE_Z85] = 0;
                if (zmq_z85_decode (curve_public_key, z85_key)) {
                    mechanism = ZMQ_CURVE;
                    return 0;
                }
            }
            break;

        case ZMQ_CURVE_SECRETKEY:
            if (optvallen_ == CURVE_KEYSIZE) {
                memcpy (curve_secret_key, optval_, CURVE_KEYSIZE);
                mechanism = ZMQ_CURVE;
                return 0;
            }
            else
            if (optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                if (zmq_z85_decode (curve_secret_key, (char *) optval_)) {
                    mechanism = ZMQ_CURVE;
                    return 0;
                }
            }
            else
            //  Deprecated, not symmetrical with zmq_getsockopt
            if (optvallen_ == CURVE_KEYSIZE_Z85) {
                char z85_key [CURVE_KEYSIZE_Z85 + 1];
                memcpy (z85_key, (char *) optval_, CURVE_KEYSIZE_Z85);
                z85_key [CURVE_KEYSIZE_Z85] = 0;
                if (zmq_z85_decode (curve_secret_key, z85_key)) {
                    mechanism = ZMQ_CURVE;
                    return 0;
                }
            }
            break;

        case ZMQ_CURVE_SERVERKEY:
            if (optvallen_ == CURVE_KEYSIZE) {
                memcpy (curve_server_key, optval_, CURVE_KEYSIZE);
                mechanism = ZMQ_CURVE;
                as_server = 0;
                return 0;
            }
            else
            if (optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                if (zmq_z85_decode (curve_server_key, (char *) optval_)) {
                    mechanism = ZMQ_CURVE;
                    as_server = 0;
                    return 0;
                }
            }
            else
            //  Deprecated, not symmetrical with zmq_getsockopt
            if (optvallen_ == CURVE_KEYSIZE_Z85) {
                char z85_key [CURVE_KEYSIZE_Z85 + 1];
                memcpy (z85_key, (char *) optval_, CURVE_KEYSIZE_Z85);
                z85_key [CURVE_KEYSIZE_Z85] = 0;
                if (zmq_z85_decode (curve_server_key, z85_key)) {
                    mechanism = ZMQ_CURVE;
                    as_server = 0;
                    return 0;
                }
            }
            break;
#       endif

        case ZMQ_CONFLATE:
            if (is_int && (value == 0 || value == 1)) {
                conflate = (value != 0);
                return 0;
            }
            break;

        //  If libgssapi isn't installed, these options provoke EINVAL
#       ifdef HAVE_LIBGSSAPI_KRB5
        case ZMQ_GSSAPI_SERVER:
            if (is_int && (value == 0 || value == 1)) {
                as_server = value;
                mechanism = ZMQ_GSSAPI;
                return 0;
            }
            break;

        case ZMQ_GSSAPI_PRINCIPAL:
            if (optvallen_ > 0 && optvallen_ < 256 && optval_ != NULL) {
                gss_principal.assign ((const char *) optval_, optvallen_);
                mechanism = ZMQ_GSSAPI;
                return 0;
            }
            break;

        case ZMQ_GSSAPI_SERVICE_PRINCIPAL:
            if (optvallen_ > 0 && optvallen_ < 256 && optval_ != NULL) {
                gss_service_principal.assign ((const char *) optval_, optvallen_);
                mechanism = ZMQ_GSSAPI;
                as_server = 0;
                return 0;
            }
            break;

        case ZMQ_GSSAPI_PLAINTEXT:
            if (is_int && (value == 0 || value == 1)) {
                gss_plaintext = (value != 0);
                return 0;
            }
            break;
#       endif

        case ZMQ_HANDSHAKE_IVL:
            if (is_int && value >= 0) {
                handshake_ivl = value;
                return 0;
            }
            break;

        case ZMQ_INVERT_MATCHING:
            if (is_int) {
                invert_matching = (value != 0);
                return 0;
            }
            break;

        case ZMQ_HEARTBEAT_IVL:
            if (is_int && value >= 0) {
                heartbeat_interval = value;
                return 0;
            }
            break;

        case ZMQ_HEARTBEAT_TTL:
            // Convert this to deciseconds from milliseconds
            value = value / 100;
            if (is_int && value >= 0 && value <= 6553) {
                heartbeat_ttl = (uint16_t)value;
                return 0;
            }
            break;

        case ZMQ_HEARTBEAT_TIMEOUT:
            if (is_int && value >= 0) {
                heartbeat_timeout = value;
                return 0;
            }
            break;

#       ifdef ZMQ_HAVE_VMCI
        case ZMQ_VMCI_BUFFER_SIZE:
            if (optvallen_ == sizeof (uint64_t)) {
                vmci_buffer_size = *((uint64_t*) optval_);
                return 0;
            }
            break;

        case ZMQ_VMCI_BUFFER_MIN_SIZE:
            if (optvallen_ == sizeof (uint64_t)) {
                vmci_buffer_min_size = *((uint64_t*) optval_);
                return 0;
            }
            break;

        case ZMQ_VMCI_BUFFER_MAX_SIZE:
            if (optvallen_ == sizeof (uint64_t)) {
                vmci_buffer_max_size = *((uint64_t*) optval_);
                return 0;
            }
            break;

        case ZMQ_VMCI_CONNECT_TIMEOUT:
            if (optvallen_ == sizeof (int)) {
                vmci_connect_timeout = *((int*) optval_);
                return 0;
            }
            break;
#       endif

        default:
#if defined (ZMQ_ACT_MILITANT)
            //  There are valid scenarios for probing with unknown socket option
            //  values, e.g. to check if security is enabled or not. This will not
            //  provoke a militant assert. However, passing bad values to a valid
            //  socket option will, if ZMQ_ACT_MILITANT is defined.
            malformed = false;
#endif
            break;
    }
#if defined (ZMQ_ACT_MILITANT)
    //  There is no valid use case for passing an error back to the application
    //  when it sent malformed arguments to a socket option. Use ./configure
    //  --with-militant to enable this checking.
    if (malformed)
        zmq_assert (false);
#endif
    errno = EINVAL;
    return -1;
}

int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_) const
{
    bool is_int = (*optvallen_ == sizeof (int));
    int *value = (int *) optval_;
#if defined (ZMQ_ACT_MILITANT)
    bool malformed = true;          //  Did caller pass a bad option value?
#endif

    switch (option_) {
        case ZMQ_SNDHWM:
            if (is_int) {
                *value = sndhwm;
                return 0;
            }
            break;

        case ZMQ_RCVHWM:
            if (is_int) {
                *value = rcvhwm;
                return 0;
            }
            break;

        case ZMQ_AFFINITY:
            if (*optvallen_ == sizeof (uint64_t)) {
                *((uint64_t *) optval_) = affinity;
                return 0;
            }
            break;

        case ZMQ_IDENTITY:
            if (*optvallen_ >= identity_size) {
                memcpy (optval_, identity, identity_size);
                *optvallen_ = identity_size;
                return 0;
            }
            break;

        case ZMQ_RATE:
            if (is_int) {
                *value = rate;
                return 0;
            }
            break;

        case ZMQ_RECOVERY_IVL:
            if (is_int) {
                *value = recovery_ivl;
                return 0;
            }
            break;

        case ZMQ_SNDBUF:
            if (is_int) {
                *value = sndbuf;
                return 0;
            }
            break;

        case ZMQ_RCVBUF:
            if (is_int) {
                *value = rcvbuf;
                return 0;
            }
            break;

        case ZMQ_TOS:
            if (is_int) {
                *value = tos;
                return 0;
            }
            break;

        case ZMQ_TYPE:
            if (is_int) {
                *value = type;
                return 0;
            }
            break;

        case ZMQ_LINGER:
            if (is_int) {
                *value = linger;
                return 0;
            }
            break;

        case ZMQ_CONNECT_TIMEOUT:
            if (is_int) {
                *value = connect_timeout;
                return 0;
            }
            break;

        case ZMQ_TCP_RETRANSMIT_TIMEOUT:
            if (is_int) {
                *value = tcp_retransmit_timeout;
                return 0;
            }
            break;

        case ZMQ_RECONNECT_IVL:
            if (is_int) {
                *value = reconnect_ivl;
                return 0;
            }
            break;

        case ZMQ_RECONNECT_IVL_MAX:
            if (is_int) {
                *value = reconnect_ivl_max;
                return 0;
            }
            break;

        case ZMQ_BACKLOG:
            if (is_int) {
                *value = backlog;
                return 0;
            }
            break;

        case ZMQ_MAXMSGSIZE:
            if (*optvallen_ == sizeof (int64_t)) {
                *((int64_t *) optval_) = maxmsgsize;
                *optvallen_ = sizeof (int64_t);
                return 0;
            }
            break;

        case ZMQ_MULTICAST_HOPS:
            if (is_int) {
                *value = multicast_hops;
                return 0;
            }
            break;

        case ZMQ_MULTICAST_MAXTPDU:
            if (is_int) {
                *value = multicast_maxtpdu;
                return 0;
            }
            break;

        case ZMQ_RCVTIMEO:
            if (is_int) {
                *value = rcvtimeo;
                return 0;
            }
            break;

        case ZMQ_SNDTIMEO:
            if (is_int) {
                *value = sndtimeo;
                return 0;
            }
            break;

        case ZMQ_IPV4ONLY:
            if (is_int) {
                *value = 1 - ipv6;
                return 0;
            }
            break;

        case ZMQ_IPV6:
            if (is_int) {
                *value = ipv6;
                return 0;
            }
            break;

        case ZMQ_IMMEDIATE:
            if (is_int) {
                *value = immediate;
                return 0;
            }
            break;

        case ZMQ_SOCKS_PROXY:
            if (*optvallen_ >= socks_proxy_address.size () + 1) {
                memcpy (optval_, socks_proxy_address.c_str (), socks_proxy_address.size () + 1);
                *optvallen_ = socks_proxy_address.size () + 1;
                return 0;
            }
            break;

        case ZMQ_TCP_KEEPALIVE:
            if (is_int) {
                *value = tcp_keepalive;
                return 0;
            }
            break;

        case ZMQ_TCP_KEEPALIVE_CNT:
            if (is_int) {
                *value = tcp_keepalive_cnt;
                return 0;
            }
            break;

        case ZMQ_TCP_KEEPALIVE_IDLE:
            if (is_int) {
                *value = tcp_keepalive_idle;
                return 0;
            }
            break;

        case ZMQ_TCP_KEEPALIVE_INTVL:
            if (is_int) {
                *value = tcp_keepalive_intvl;
                return 0;
            }
            break;

        case ZMQ_TCP_SEND_BUFFER:
            if (is_int) {
                *value = tcp_send_buffer_size;
                return 0;
            }
            break;

        case ZMQ_TCP_RECV_BUFFER:
            if (is_int) {
                *value = tcp_recv_buffer_size;
                return 0;
            }
            break;

        case ZMQ_MECHANISM:
            if (is_int) {
                *value = mechanism;
                return 0;
            }
            break;

        case ZMQ_PLAIN_SERVER:
            if (is_int) {
                *value = as_server && mechanism == ZMQ_PLAIN;
                return 0;
            }
            break;

        case ZMQ_PLAIN_USERNAME:
            if (*optvallen_ >= plain_username.size () + 1) {
                memcpy (optval_, plain_username.c_str (), plain_username.size () + 1);
                *optvallen_ = plain_username.size () + 1;
                return 0;
            }
            break;

        case ZMQ_PLAIN_PASSWORD:
            if (*optvallen_ >= plain_password.size () + 1) {
                memcpy (optval_, plain_password.c_str (), plain_password.size () + 1);
                *optvallen_ = plain_password.size () + 1;
                return 0;
            }
            break;

        case ZMQ_ZAP_DOMAIN:
            if (*optvallen_ >= zap_domain.size () + 1) {
                memcpy (optval_, zap_domain.c_str (), zap_domain.size () + 1);
                *optvallen_ = zap_domain.size () + 1;
                return 0;
            }
            break;

        //  If libsodium isn't installed, these options provoke EINVAL
#       ifdef HAVE_LIBSODIUM
        case ZMQ_CURVE_SERVER:
            if (is_int) {
                *value = as_server && mechanism == ZMQ_CURVE;
                return 0;
            }
            break;

        case ZMQ_CURVE_PUBLICKEY:
            if (*optvallen_ == CURVE_KEYSIZE) {
                memcpy (optval_, curve_public_key, CURVE_KEYSIZE);
                return 0;
            }
            else
            if (*optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                zmq_z85_encode ((char *) optval_, curve_public_key, CURVE_KEYSIZE);
                return 0;
            }
            break;

        case ZMQ_CURVE_SECRETKEY:
            if (*optvallen_ == CURVE_KEYSIZE) {
                memcpy (optval_, curve_secret_key, CURVE_KEYSIZE);
                return 0;
            }
            else
            if (*optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                zmq_z85_encode ((char *) optval_, curve_secret_key, CURVE_KEYSIZE);
                return 0;
            }
            break;

        case ZMQ_CURVE_SERVERKEY:
            if (*optvallen_ == CURVE_KEYSIZE) {
                memcpy (optval_, curve_server_key, CURVE_KEYSIZE);
                return 0;
            }
            else
            if (*optvallen_ == CURVE_KEYSIZE_Z85 + 1) {
                zmq_z85_encode ((char *) optval_, curve_server_key, CURVE_KEYSIZE);
                return 0;
            }
            break;
#       endif

        case ZMQ_CONFLATE:
            if (is_int) {
                *value = conflate;
                return 0;
            }
            break;

        //  If libgssapi isn't installed, these options provoke EINVAL
#       ifdef HAVE_LIBGSSAPI_KRB5
        case ZMQ_GSSAPI_SERVER:
            if (is_int) {
                *value = as_server && mechanism == ZMQ_GSSAPI;
                return 0;
            }
            break;

        case ZMQ_GSSAPI_PRINCIPAL:
            if (*optvallen_ >= gss_principal.size () + 1) {
                memcpy (optval_, gss_principal.c_str (), gss_principal.size () + 1);
                *optvallen_ = gss_principal.size () + 1;
                return 0;
            }
            break;

        case ZMQ_GSSAPI_SERVICE_PRINCIPAL:
            if (*optvallen_ >= gss_service_principal.size () + 1) {
                memcpy (optval_, gss_service_principal.c_str (), gss_service_principal.size () + 1);
                *optvallen_ = gss_service_principal.size () + 1;
                return 0;
            }
            break;

        case ZMQ_GSSAPI_PLAINTEXT:
            if (is_int) {
                *value = gss_plaintext;
                return 0;
            }
            break;
#endif

        case ZMQ_HANDSHAKE_IVL:
            if (is_int) {
                *value = handshake_ivl;
                return 0;
            }
            break;

        case ZMQ_INVERT_MATCHING:
            if (is_int) {
                *value = invert_matching;
                return 0;
            }
            break;

        case ZMQ_HEARTBEAT_IVL:
            if (is_int) {
                *value = heartbeat_interval;
                return 0;
            }
            break;

        case ZMQ_HEARTBEAT_TTL:
            if (is_int) {
                // Convert the internal deciseconds value to milliseconds
                *value = heartbeat_ttl * 100;
                return 0;
            }
            break;

        case ZMQ_HEARTBEAT_TIMEOUT:
            if (is_int) {
                *value = heartbeat_timeout;
                return 0;
            }
            break;

        default:
#if defined (ZMQ_ACT_MILITANT)
            malformed = false;
#endif
            break;
    }
#if defined (ZMQ_ACT_MILITANT)
    if (malformed)
        zmq_assert (false);
#endif
    errno = EINVAL;
    return -1;
}

bool zmq::options_t::is_valid (int option_) const
{
    return true;
}