/*
    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>
#include <sstream>

#include "tcp_address.hpp"
#include "platform.hpp"
#include "stdint.hpp"
#include "err.hpp"
#include "ip.hpp"

#ifdef ZMQ_HAVE_WINDOWS
#include "windows.hpp"
#else
#include <sys/types.h>
#include <arpa/inet.h>
#include <netinet/tcp.h>
#include <netdb.h>
#endif

#ifdef ZMQ_HAVE_SOLARIS

#include <sys/sockio.h>
#include <net/if.h>
#include <unistd.h>
#include <stdlib.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.
    (void) 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

#include <sys/types.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <net/if.h>

int zmq::tcp_address_t::resolve_nic_name (const char *nic_, bool ipv6_, bool is_src_)
{
    //  TODO: Unused parameter, IPv6 support not implemented for AIX or HP/UX.
    (void) ipv6_;

    //  Create a socket.
    const int sd = open_socket (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;
    }
    if (is_src_)
        memcpy (&source_address.ipv4.sin_addr,
            &((sockaddr_in*) &ifr.ifr_addr)->sin_addr, sizeof (struct in_addr));
    else
       memcpy (&address.ipv4.sin_addr,
            &((sockaddr_in*) &ifr.ifr_addr)->sin_addr, sizeof (struct in_addr));

    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_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;
    const int rc = getifaddrs (&ifa);
    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 == AF_INET || (ipv6_ && family == AF_INET6))
        && !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;
}

#else

//  On other platforms we assume there are no sane interface names.
//  This is true especially of Windows.
int zmq::tcp_address_t::resolve_nic_name (const char *nic_, bool ipv6_, bool is_src_)
{
    //  All unused parameters.
    (void) nic_;
    (void) 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;
        memcpy (&ip6_addr.sin6_addr, &in6addr_any, sizeof in6addr_any);
        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 && !defined ZMQ_HAVE_FREEBSD
    //  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.
    //  Note: While the AI_V4MAPPED flag is defined on FreeBSD system,
    //  it is not supported here. See libzmq issue #331.
    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 (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 && !defined ZMQ_HAVE_FREEBSD
    //  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.
    //  Note: While the AI_V4MAPPED flag is defined on FreeBSD system,
    //  it is not supported here. See libzmq issue #331.
    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
    const int rc = getaddrinfo (hostname_, NULL, &req, &res);
    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);
    memset (&source_address, 0, sizeof source_address);
}

zmq::tcp_address_t::tcp_address_t (const sockaddr *sa, socklen_t sa_len) :
    _has_src_addr (false)
{
    zmq_assert (sa && sa_len > 0);

    memset (&address, 0, sizeof address);
    memset (&source_address, 0, sizeof source_address);
    if (sa->sa_family == AF_INET && sa_len >= (socklen_t) sizeof address.ipv4)
        memcpy (&address.ipv4, sa, sizeof address.ipv4);
    else
    if (sa->sa_family == AF_INET6 && sa_len >= (socklen_t) sizeof address.ipv6)
        memcpy (&address.ipv6, sa, sizeof address.ipv6);
}

zmq::tcp_address_t::~tcp_address_t ()
{
}

int zmq::tcp_address_t::resolve (const char *name_, bool local_, bool ipv6_, bool is_src_)
{
    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);
            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);

    //  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;
        }
    }

    //  Resolve the IP address.
    int rc;
    if (local_)
        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);
        else
            source_address.ipv4.sin_port = htons (port);
    }
    else {
        if (address.generic.sa_family == AF_INET6)
            address.ipv6.sin6_port = htons (port);
        else
            address.ipv4.sin_port = htons (port);
    }

    return 0;
}

int zmq::tcp_address_t::to_string (std::string &addr_)
{
    if (address.generic.sa_family != AF_INET
    &&  address.generic.sa_family != AF_INET6) {
        addr_.clear ();
        return -1;
    }

    //  Not using service resolv because of
    //  https://github.com/zeromq/libzmq/commit/1824574f9b5a8ce786853320e3ea09fe1f822bc4
    char hbuf [NI_MAXHOST];
    int rc = getnameinfo (addr (), addrlen (), hbuf, sizeof hbuf, NULL, 0, NI_NUMERICHOST);
    if (rc != 0) {
        addr_.clear ();
        return rc;
    }

    if (address.generic.sa_family == AF_INET6) {
        std::stringstream s;
        s << "tcp://[" << hbuf << "]:" << ntohs (address.ipv6.sin6_port);
        addr_ = s.str ();
    }
    else {
        std::stringstream s;
        s << "tcp://" << hbuf << ":" << ntohs (address.ipv4.sin_port);
        addr_ = s.str ();
    }
    return 0;
}

const sockaddr *zmq::tcp_address_t::addr () const
{
    return &address.generic;
}

socklen_t zmq::tcp_address_t::addrlen () const
{
    if (address.generic.sa_family == AF_INET6)
        return (socklen_t) sizeof address.ipv6;
    else
        return (socklen_t) sizeof address.ipv4;
}

const sockaddr *zmq::tcp_address_t::src_addr () const
{
    return &source_address.generic;
}

socklen_t zmq::tcp_address_t::src_addrlen () const
{
    if (address.generic.sa_family == AF_INET6)
        return (socklen_t) sizeof source_address.ipv6;
    else
        return (socklen_t) sizeof source_address.ipv4;
}

bool zmq::tcp_address_t::has_src_addr () const
{
    return _has_src_addr;
}

#if defined ZMQ_HAVE_WINDOWS
unsigned short zmq::tcp_address_t::family () const
#else
sa_family_t zmq::tcp_address_t::family () const
#endif
{
    return address.generic.sa_family;
}

zmq::tcp_address_mask_t::tcp_address_mask_t () :
    tcp_address_t (),
    address_mask (-1)
{
}

int zmq::tcp_address_mask_t::mask () const
{
    return address_mask;
}

int zmq::tcp_address_mask_t::resolve (const char *name_, bool ipv6_)
{
    // Find '/' at the end that separates address from the cidr mask number.
    // Allow empty mask clause and treat it like '/32' for ipv4 or '/128' for ipv6.
    std::string addr_str, mask_str;
    const char *delimiter = strrchr (name_, '/');
    if (delimiter != NULL) {
        addr_str.assign (name_, delimiter - name_);
        mask_str.assign (delimiter + 1);
        if (mask_str.empty ()) {
            errno = EINVAL;
            return -1;
        }
    }
    else
        addr_str.assign (name_);

    // Parse address part using standard routines.
    const int rc =
        tcp_address_t::resolve_hostname (addr_str.c_str (), ipv6_);
    if (rc != 0)
        return rc;

    // Parse the cidr mask number.
    if (mask_str.empty ()) {
        if (address.generic.sa_family == AF_INET6)
            address_mask = 128;
        else
            address_mask = 32;
    }
    else
    if (mask_str == "0")
        address_mask = 0;
    else {
        const int mask = atoi (mask_str.c_str ());
        if (
            (mask < 1) ||
            (address.generic.sa_family == AF_INET6 && mask > 128) ||
            (address.generic.sa_family != AF_INET6 && mask > 32)
        ) {
            errno = EINVAL;
            return -1;
        }
        address_mask = mask;
    }

    return 0;
}

int zmq::tcp_address_mask_t::to_string (std::string &addr_)
{
    if (address.generic.sa_family != AF_INET
    &&  address.generic.sa_family != AF_INET6) {
        addr_.clear ();
        return -1;
    }
    if (address_mask == -1) {
        addr_.clear ();
        return -1;
    }

    char hbuf [NI_MAXHOST];
    int rc = getnameinfo (addr (), addrlen (), hbuf, sizeof hbuf, NULL, 0, NI_NUMERICHOST);
    if (rc != 0) {
        addr_.clear ();
        return rc;
    }

    if (address.generic.sa_family == AF_INET6) {
        std::stringstream s;
        s << "[" << hbuf << "]/" << address_mask;
        addr_ = s.str ();
    }
    else {
        std::stringstream s;
        s << hbuf << "/" << address_mask;
        addr_ = s.str ();
    }
    return 0;
}

bool zmq::tcp_address_mask_t::match_address (const struct sockaddr *ss, const socklen_t ss_len) const
{
    zmq_assert (address_mask != -1
             && ss != NULL
             && ss_len >= (socklen_t) sizeof (struct sockaddr));

    if (ss->sa_family != address.generic.sa_family)
        return false;

    if (address_mask > 0) {
        int mask;
        const uint8_t *our_bytes, *their_bytes;
        if (ss->sa_family == AF_INET6) {
            zmq_assert (ss_len == sizeof (struct sockaddr_in6));
            their_bytes = (const uint8_t *) &(((const struct sockaddr_in6 *) ss)->sin6_addr);
            our_bytes = (const uint8_t *) &address.ipv6.sin6_addr;
            mask = sizeof (struct in6_addr) * 8;
        }
        else {
            zmq_assert (ss_len == sizeof (struct sockaddr_in));
            their_bytes = (const uint8_t *) &(((const struct sockaddr_in *) ss)->sin_addr);
            our_bytes = (const uint8_t *) &address.ipv4.sin_addr;
            mask = sizeof (struct in_addr) * 8;
        }
        if (address_mask < mask)
            mask = address_mask;

        const size_t full_bytes = mask / 8;
        if (memcmp (our_bytes, their_bytes, full_bytes))
            return false;

        const uint8_t last_byte_bits = 0xffU << (8 - mask % 8);
        if (last_byte_bits) {
            if ((their_bytes [full_bytes] & last_byte_bits) != (our_bytes [full_bytes] & last_byte_bits))
                return false;
        }
    }

    return true;
}
