qnetworkinterface_unix.cpp

Go to the documentation of this file.

// Copyright (C) 2016 The Qt Company Ltd.
// Copyright (C) 2016 Intel Corporation.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qbytearray.h"
#include "qset.h"
#include "qnetworkinterface.h"
#include "qnetworkinterface_p.h"
#include "qnetworkinterface_unix_p.h"
#include "qalgorithms.h"
 
#include <QtCore/private/qduplicatetracker_p.h>
 
#ifndef QT_NO_NETWORKINTERFACE
 
#if defined(QT_NO_CLOCK_MONOTONIC)
#  include "qdatetime.h"
#endif
 
#if QT_CONFIG(getifaddrs)
# include <ifaddrs.h>
#endif
 
#ifdef QT_LINUXBASE
#  include <arpa/inet.h>
#  ifndef SIOCGIFBRDADDR
#    define SIOCGIFBRDADDR 0x8919
#  endif
#endif // QT_LINUXBASE
 
#include <qplatformdefs.h>
 
QT_BEGIN_NAMESPACE
 
static QHostAddress addressFromSockaddr(sockaddr *sa, int ifindex = 0, const QString &ifname = QString())
{
    QHostAddress address;
    if (!sa)
        return address;
 
    if (sa->sa_family == AF_INET)
        address.setAddress(htonl(((sockaddr_in *)sa)->sin_addr.s_addr));
    else if (sa->sa_family == AF_INET6) {
        address.setAddress(((sockaddr_in6 *)sa)->sin6_addr.s6_addr);
        int scope = ((sockaddr_in6 *)sa)->sin6_scope_id;
        if (scope && scope == ifindex) {
            // this is the most likely scenario:
            // a scope ID in a socket is that of the interface this address came from
            address.setScopeId(ifname);
        } else if (scope) {
            address.setScopeId(QNetworkInterfaceManager::interfaceNameFromIndex(scope));
        }
    }
    return address;
}
 
template <typename Req> [[maybe_unused]]
static auto &ifreq_index(Req &req, std::enable_if_t<sizeof(std::declval<Req>().ifr_index) != 0, int> = 0)
{
    return req.ifr_index;
}
 
template <typename Req> [[maybe_unused]]
static auto &ifreq_index(Req &req, std::enable_if_t<sizeof(std::declval<Req>().ifr_ifindex) != 0, int> = 0)
{
    return req.ifr_ifindex;
}
 
uint QNetworkInterfaceManager::interfaceIndexFromName(const QString &name)
{
#if QT_CONFIG(ipv6ifname)
    return ::if_nametoindex(name.toLatin1().constData());
#elif defined(SIOCGIFINDEX)
    struct ifreq req;
    int socket = qt_safe_socket(AF_INET, SOCK_STREAM, 0);
    if (socket < 0)
        return 0;
 
    const QByteArray name8bit = name.toLatin1();
    memset(&req, 0, sizeof(ifreq));
    if (!name8bit.isNull())
        memcpy(req.ifr_name, name8bit.data(), qMin(size_t(name8bit.length()) + 1, sizeof(req.ifr_name) - 1));
 
    uint id = 0;
    if (qt_safe_ioctl(socket, SIOCGIFINDEX, &req) >= 0)
        id = ifreq_index(req);
    qt_safe_close(socket);
    return id;
#else
    Q_UNUSED(name);
    return 0;
#endif
}
 
QString QNetworkInterfaceManager::interfaceNameFromIndex(uint index)
{
#if QT_CONFIG(ipv6ifname)
    char buf[IF_NAMESIZE];
    if (::if_indextoname(index, buf))
        return QString::fromLatin1(buf);
#elif defined(SIOCGIFNAME)
    struct ifreq req;
    int socket = qt_safe_socket(AF_INET, SOCK_STREAM, 0);
    if (socket >= 0) {
        memset(&req, 0, sizeof(ifreq));
        ifreq_index(req) = index;
        if (qt_safe_ioctl(socket, SIOCGIFNAME, &req) >= 0) {
            qt_safe_close(socket);
            return QString::fromLatin1(req.ifr_name);
        }
        qt_safe_close(socket);
    }
#endif
    return QString::number(uint(index));
}
 
static int getMtu(int socket, struct ifreq *req)
{
#ifdef SIOCGIFMTU
    if (qt_safe_ioctl(socket, SIOCGIFMTU, req) == 0)
        return req->ifr_mtu;
#endif
    return 0;
}
 
#if !QT_CONFIG(getifaddrs)
// getifaddrs not available
 
static QSet<QByteArray> interfaceNames(int socket)
{
    QSet<QByteArray> result;
#if !QT_CONFIG(ipv6ifname)
    QByteArray storageBuffer;
    struct ifconf interfaceList;
    static const int STORAGEBUFFER_GROWTH = 256;
 
    forever {
        // grow the storage buffer
        storageBuffer.resize(storageBuffer.size() + STORAGEBUFFER_GROWTH);
        interfaceList.ifc_buf = storageBuffer.data();
        interfaceList.ifc_len = storageBuffer.size();
 
        // get the interface list
        if (qt_safe_ioctl(socket, SIOCGIFCONF, &interfaceList) >= 0) {
            if (int(interfaceList.ifc_len + sizeof(ifreq) + 64) < storageBuffer.size()) {
                // if the buffer was big enough, break
                storageBuffer.resize(interfaceList.ifc_len);
                break;
            }
        } else {
            // internal error
            return result;
        }
        if (storageBuffer.size() > 100000) {
            // out of space
            return result;
        }
    }
 
    int interfaceCount = interfaceList.ifc_len / sizeof(ifreq);
    for (int i = 0; i < interfaceCount; ++i) {
        QByteArray name = QByteArray(interfaceList.ifc_req[i].ifr_name);
        if (!name.isEmpty())
            result << name;
    }
 
    return result;
#else
    Q_UNUSED(socket);
 
    // use if_nameindex
    struct if_nameindex *interfaceList = ::if_nameindex();
    for (struct if_nameindex *ptr = interfaceList; ptr && ptr->if_name; ++ptr)
        result << ptr->if_name;
 
    if_freenameindex(interfaceList);
    return result;
#endif
}
 
static QNetworkInterfacePrivate *findInterface(int socket, QList<QNetworkInterfacePrivate *> &interfaces,
                                               struct ifreq &req)
{
    QNetworkInterfacePrivate *iface = nullptr;
    int ifindex = 0;
 
#if QT_CONFIG(ipv6ifname) || defined(SIOCGIFINDEX)
    // Get the interface index
#  ifdef SIOCGIFINDEX
    if (qt_safe_ioctl(socket, SIOCGIFINDEX, &req) >= 0)
        ifindex = ifreq_index(req);
#  else
    ifindex = if_nametoindex(req.ifr_name);
#  endif
 
    // find the interface data
    QList<QNetworkInterfacePrivate *>::Iterator if_it = interfaces.begin();
    for ( ; if_it != interfaces.end(); ++if_it)
        if ((*if_it)->index == ifindex) {
            // existing interface
            iface = *if_it;
            break;
        }
#else
    Q_UNUSED(socket);
    // Search by name
    QList<QNetworkInterfacePrivate *>::Iterator if_it = interfaces.begin();
    for ( ; if_it != interfaces.end(); ++if_it)
        if ((*if_it)->name == QLatin1StringView(req.ifr_name)) {
            // existing interface
            iface = *if_it;
            break;
        }
#endif
 
    if (!iface) {
        // new interface, create data:
        iface = new QNetworkInterfacePrivate;
        iface->index = ifindex;
        interfaces << iface;
    }
 
    return iface;
}
 
static QList<QNetworkInterfacePrivate *> interfaceListing()
{
    QList<QNetworkInterfacePrivate *> interfaces;
 
    int socket;
    if ((socket = qt_safe_socket(AF_INET, SOCK_STREAM, IPPROTO_IP)) == -1)
        return interfaces;      // error
 
    QSet<QByteArray> names = interfaceNames(socket);
    QSet<QByteArray>::ConstIterator it = names.constBegin();
    for ( ; it != names.constEnd(); ++it) {
        ifreq req;
        memset(&req, 0, sizeof(ifreq));
        if (!it->isNull())
            memcpy(req.ifr_name, it->constData(), qMin(size_t(it->length()) + 1, sizeof(req.ifr_name) - 1));
 
        QNetworkInterfacePrivate *iface = findInterface(socket, interfaces, req);
 
#ifdef SIOCGIFNAME
        // Get the canonical name
        QByteArray oldName = req.ifr_name;
        if (qt_safe_ioctl(socket, SIOCGIFNAME, &req) >= 0) {
            iface->name = QString::fromLatin1(req.ifr_name);
 
            // reset the name:
            if (!oldName.isNull())
                memcpy(req.ifr_name, oldName.constData(), qMin(size_t(oldName.length()) + 1, sizeof(req.ifr_name) - 1));
        } else
#endif
        {
            // use this name anyways
            iface->name = QString::fromLatin1(req.ifr_name);
        }
 
        // Get interface flags
        if (qt_safe_ioctl(socket, SIOCGIFFLAGS, &req) >= 0) {
            iface->flags = convertFlags(req.ifr_flags);
        }
        iface->mtu = getMtu(socket, &req);
 
#ifdef SIOCGIFHWADDR
        // Get the HW address
        if (qt_safe_ioctl(socket, SIOCGIFHWADDR, &req) >= 0) {
            uchar *addr = (uchar *)req.ifr_addr.sa_data;
            iface->hardwareAddress = iface->makeHwAddress(6, addr);
        }
#endif
 
        // Get the address of the interface
        QNetworkAddressEntry entry;
        if (qt_safe_ioctl(socket, SIOCGIFADDR, &req) >= 0) {
            sockaddr *sa = &req.ifr_addr;
            entry.setIp(addressFromSockaddr(sa));
 
            // Get the interface broadcast address
            if (iface->flags & QNetworkInterface::CanBroadcast) {
                if (qt_safe_ioctl(socket, SIOCGIFBRDADDR, &req) >= 0) {
                    sockaddr *sa = &req.ifr_addr;
                    if (sa->sa_family == AF_INET)
                        entry.setBroadcast(addressFromSockaddr(sa));
                }
            }
 
            // Get the interface netmask
            if (qt_safe_ioctl(socket, SIOCGIFNETMASK, &req) >= 0) {
                sockaddr *sa = &req.ifr_addr;
                entry.setNetmask(addressFromSockaddr(sa));
            }
 
            iface->addressEntries << entry;
        }
    }
 
    ::close(socket);
    return interfaces;
}
 
#else
// use getifaddrs
 
// platform-specific defs:
# ifdef Q_OS_LINUX
QT_BEGIN_INCLUDE_NAMESPACE
#  include <features.h>
QT_END_INCLUDE_NAMESPACE
# endif
 
static int openSocket(int &socket)
{
    if (socket == -1)
        socket = qt_safe_socket(AF_INET, SOCK_DGRAM, 0);
    return socket;
}
 
# if defined(Q_OS_LINUX) &&  __GLIBC__ - 0 >= 2 && __GLIBC_MINOR__ - 0 >= 1 && !defined(QT_LINUXBASE)
#  include <netpacket/packet.h>
 
static QList<QNetworkInterfacePrivate *> createInterfaces(ifaddrs *rawList)
{
    Q_UNUSED(getMtu);
    Q_UNUSED(openSocket);
    QList<QNetworkInterfacePrivate *> interfaces;
    QDuplicateTracker<QString> seenInterfaces;
    QDuplicateTracker<int> seenIndexes;
 
    // On Linux, glibc, uClibc and MUSL obtain the address listing via two
    // netlink calls: first an RTM_GETLINK to obtain the interface listing,
    // then one RTM_GETADDR to get all the addresses (uClibc implementation is
    // copied from glibc; Bionic currently doesn't support getifaddrs). They
    // synthesize AF_PACKET addresses from the RTM_GETLINK responses, which
    // means by construction they currently show up first in the interface
    // listing.
    for (ifaddrs *ptr = rawList; ptr; ptr = ptr->ifa_next) {
        if (ptr->ifa_addr && ptr->ifa_addr->sa_family == AF_PACKET) {
            sockaddr_ll *sll = (sockaddr_ll *)ptr->ifa_addr;
            QNetworkInterfacePrivate *iface = new QNetworkInterfacePrivate;
            interfaces << iface;
            iface->index = sll->sll_ifindex;
            iface->name = QString::fromLatin1(ptr->ifa_name);
            iface->flags = convertFlags(ptr->ifa_flags);
            iface->hardwareAddress = iface->makeHwAddress(sll->sll_halen, (uchar*)sll->sll_addr);
 
            const bool sawIfaceIndex = seenIndexes.hasSeen(iface->index);
            Q_ASSERT(!sawIfaceIndex);
            (void)seenInterfaces.hasSeen(iface->name);
        }
    }
 
    // see if we missed anything:
    // - virtual interfaces with no HW address have no AF_PACKET
    // - interface labels have no AF_PACKET, but shouldn't be shown as a new interface
    for (ifaddrs *ptr = rawList; ptr; ptr = ptr->ifa_next) {
        if (!ptr->ifa_addr || ptr->ifa_addr->sa_family != AF_PACKET) {
            QString name = QString::fromLatin1(ptr->ifa_name);
            if (seenInterfaces.hasSeen(name))
                continue;
 
            int ifindex = if_nametoindex(ptr->ifa_name);
            if (seenIndexes.hasSeen(ifindex))
                continue;
 
            QNetworkInterfacePrivate *iface = new QNetworkInterfacePrivate;
            interfaces << iface;
            iface->name = name;
            iface->flags = convertFlags(ptr->ifa_flags);
            iface->index = ifindex;
        }
    }
 
    return interfaces;
}
 
static void getAddressExtraInfo(QNetworkAddressEntry *entry, struct sockaddr *sa, const char *ifname)
{
    Q_UNUSED(entry);
    Q_UNUSED(sa);
    Q_UNUSED(ifname);
}
 
# elif defined(Q_OS_BSD4)
QT_BEGIN_INCLUDE_NAMESPACE
#  include <net/if_dl.h>
#if defined(QT_PLATFORM_UIKIT)
#  include "qnetworkinterface_uikit_p.h"
#  include <net/if_types.h>
#else
#  include <net/if_media.h>
#  include <net/if_types.h>
#  include <netinet/in_var.h>
#endif // QT_PLATFORM_UIKIT
QT_END_INCLUDE_NAMESPACE
 
static QNetworkInterface::InterfaceType probeIfType(int socket, int iftype, struct ifmediareq *req)
{
    // Determine the interface type.
 
    // On Darwin, these are #defines, but on FreeBSD they're just an
    // enum, so we can't #ifdef them. Use the authoritative list from
    // https://www.iana.org/assignments/smi-numbers/smi-numbers.xhtml#smi-numbers-5
    switch (iftype) {
    case IFT_PPP:
        return QNetworkInterface::Ppp;
 
    case IFT_LOOP:
        return QNetworkInterface::Loopback;
 
    case IFT_SLIP:
        return QNetworkInterface::Slip;
 
    case 0x47:      // IFT_IEEE80211
        return QNetworkInterface::Ieee80211;
 
    case IFT_IEEE1394:
        return QNetworkInterface::Ieee1394;
 
    case IFT_GIF:
    case IFT_STF:
        return QNetworkInterface::Virtual;
    }
 
    // For the remainder (including Ethernet), let's try SIOGIFMEDIA
    req->ifm_count = 0;
    if (qt_safe_ioctl(socket, SIOCGIFMEDIA, req) == 0) {
        // see https://man.openbsd.org/ifmedia.4
 
        switch (IFM_TYPE(req->ifm_current)) {
        case IFM_ETHER:
            return QNetworkInterface::Ethernet;
 
#ifdef IFM_FDDI
        case IFM_FDDI:
            return QNetworkInterface::Fddi;
#endif
 
        case IFM_IEEE80211:
            return QNetworkInterface::Ieee80211;
        }
    }
 
    return QNetworkInterface::Unknown;
}
 
static QList<QNetworkInterfacePrivate *> createInterfaces(ifaddrs *rawList)
{
    QList<QNetworkInterfacePrivate *> interfaces;
    union {
        struct ifmediareq mediareq;
        struct ifreq req;
    };
    int socket = -1;
    memset(&mediareq, 0, sizeof(mediareq));
 
    // ensure both structs start with the name field, of size IFNAMESIZ
    static_assert(sizeof(mediareq.ifm_name) == sizeof(req.ifr_name));
    static_assert(offsetof(struct ifmediareq, ifm_name) == 0);
    static_assert(offsetof(struct ifreq, ifr_name) == 0);
 
    // on NetBSD we use AF_LINK and sockaddr_dl
    // scan the list for that family
    for (ifaddrs *ptr = rawList; ptr; ptr = ptr->ifa_next)
        if (ptr->ifa_addr && ptr->ifa_addr->sa_family == AF_LINK) {
            QNetworkInterfacePrivate *iface = new QNetworkInterfacePrivate;
            interfaces << iface;
 
            sockaddr_dl *sdl = (sockaddr_dl *)ptr->ifa_addr;
            iface->index = sdl->sdl_index;
            iface->name = QString::fromLatin1(ptr->ifa_name);
            iface->flags = convertFlags(ptr->ifa_flags);
            iface->hardwareAddress = iface->makeHwAddress(sdl->sdl_alen, (uchar*)LLADDR(sdl));
 
            qstrncpy(mediareq.ifm_name, ptr->ifa_name, sizeof(mediareq.ifm_name));
            iface->type = probeIfType(openSocket(socket), sdl->sdl_type, &mediareq);
            iface->mtu = getMtu(socket, &req);
        }
 
    if (socket != -1)
        qt_safe_close(socket);
    return interfaces;
}
 
static void getAddressExtraInfo(QNetworkAddressEntry *entry, struct sockaddr *sa, const char *ifname)
{
    // get IPv6 address lifetimes
    if (sa->sa_family != AF_INET6)
        return;
 
    struct in6_ifreq ifr;
 
    int s6 = qt_safe_socket(AF_INET6, SOCK_DGRAM, 0);
    if (Q_UNLIKELY(s6 < 0)) {
        qErrnoWarning("QNetworkInterface: could not create IPv6 socket");
        return;
    }
 
    qstrncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 
    // get flags
    ifr.ifr_addr = *reinterpret_cast<struct sockaddr_in6 *>(sa);
    if (qt_safe_ioctl(s6, SIOCGIFAFLAG_IN6, &ifr) < 0) {
        qt_safe_close(s6);
        return;
    }
    int flags = ifr.ifr_ifru.ifru_flags6;
    QNetworkInterfacePrivate::calculateDnsEligibility(entry,
                                                      flags & IN6_IFF_TEMPORARY,
                                                      flags & IN6_IFF_DEPRECATED);
 
    // get lifetimes
    ifr.ifr_addr = *reinterpret_cast<struct sockaddr_in6 *>(sa);
    if (qt_safe_ioctl(s6, SIOCGIFALIFETIME_IN6, &ifr) < 0) {
        qt_safe_close(s6);
        return;
    }
    qt_safe_close(s6);
 
    auto toDeadline = [](time_t when) {
        QDeadlineTimer deadline = QDeadlineTimer::Forever;
        if (when) {
#if defined(QT_NO_CLOCK_MONOTONIC)
            // no monotonic clock
            deadline.setPreciseRemainingTime(when - QDateTime::currentSecsSinceEpoch());
#else
            deadline.setPreciseDeadline(when);
#endif
        }
        return deadline;
    };
    entry->setAddressLifetime(toDeadline(ifr.ifr_ifru.ifru_lifetime.ia6t_preferred),
                              toDeadline(ifr.ifr_ifru.ifru_lifetime.ia6t_expire));
}
 
# else  // Generic version
 
static QList<QNetworkInterfacePrivate *> createInterfaces(ifaddrs *rawList)
{
    QList<QNetworkInterfacePrivate *> interfaces;
    int socket = -1;
 
    // make sure there's one entry for each interface
    for (ifaddrs *ptr = rawList; ptr; ptr = ptr->ifa_next) {
        // Get the interface index
        int ifindex = if_nametoindex(ptr->ifa_name);
 
        QList<QNetworkInterfacePrivate *>::Iterator if_it = interfaces.begin();
        for ( ; if_it != interfaces.end(); ++if_it)
            if ((*if_it)->index == ifindex)
                // this one has been added already
                break;
 
        if (if_it == interfaces.end()) {
            // none found, create
            QNetworkInterfacePrivate *iface = new QNetworkInterfacePrivate;
            interfaces << iface;
 
            iface->index = ifindex;
            iface->name = QString::fromLatin1(ptr->ifa_name);
            iface->flags = convertFlags(ptr->ifa_flags);
 
            if ((socket = openSocket(socket)) >= 0) {
                struct ifreq ifr;
                qstrncpy(ifr.ifr_name, ptr->ifa_name, sizeof(ifr.ifr_name));
                iface->mtu = getMtu(socket, &ifr);
            }
        }
    }
 
    if (socket != -1)
        qt_safe_close(socket);
 
    return interfaces;
}
 
static void getAddressExtraInfo(QNetworkAddressEntry *entry, struct sockaddr *sa, const char *ifname)
{
    Q_UNUSED(entry);
    Q_UNUSED(sa);
    Q_UNUSED(ifname);
}
# endif
 
static QList<QNetworkInterfacePrivate *> interfaceListing()
{
    QList<QNetworkInterfacePrivate *> interfaces;
 
    ifaddrs *interfaceListing;
    if (getifaddrs(&interfaceListing) == -1) {
        // error
        return interfaces;
    }
 
    interfaces = createInterfaces(interfaceListing);
    for (ifaddrs *ptr = interfaceListing; ptr; ptr = ptr->ifa_next) {
        // Find the interface
        QLatin1StringView name(ptr->ifa_name);
        QNetworkInterfacePrivate *iface = nullptr;
        QList<QNetworkInterfacePrivate *>::Iterator if_it = interfaces.begin();
        for ( ; if_it != interfaces.end(); ++if_it)
            if ((*if_it)->name == name) {
                // found this interface already
                iface = *if_it;
                break;
            }
 
        if (!iface) {
            // it may be an interface label, search by interface index
            int ifindex = if_nametoindex(ptr->ifa_name);
            for (if_it = interfaces.begin(); if_it != interfaces.end(); ++if_it)
                if ((*if_it)->index == ifindex) {
                    // found this interface already
                    iface = *if_it;
                    break;
                }
        }
 
        if (!iface) {
            // skip all non-IP interfaces
            continue;
        }
 
        QNetworkAddressEntry entry;
        entry.setIp(addressFromSockaddr(ptr->ifa_addr, iface->index, iface->name));
        if (entry.ip().isNull())
            // could not parse the address
            continue;
 
        entry.setNetmask(addressFromSockaddr(ptr->ifa_netmask, iface->index, iface->name));
        if (iface->flags & QNetworkInterface::CanBroadcast)
            entry.setBroadcast(addressFromSockaddr(ptr->ifa_broadaddr, iface->index, iface->name));
        getAddressExtraInfo(&entry, ptr->ifa_addr, name.latin1());
 
        iface->addressEntries << entry;
    }
 
    freeifaddrs(interfaceListing);
    return interfaces;
}
#endif
 
QList<QNetworkInterfacePrivate *> QNetworkInterfaceManager::scan()
{
    return interfaceListing();
}
 
QT_END_NAMESPACE
 
#endif // QT_NO_NETWORKINTERFACE