util-ioctl.c

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/* Copyright (C) 2010 Open Information Security Foundation
 *
 * You can copy, redistribute or modify this Program under the terms of
 * the GNU General Public License version 2 as published by the Free
 * Software Foundation.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */
 
/**
 * \file
 *
 * \author Eric Leblond <eric@regit.org>
 * \author Victor Julien <victor@inliniac.net>
 */
 
#include "suricata-common.h"
#include "util-ioctl.h"
#include "util-device-private.h"
#include "conf.h"
#include "decode.h"
#include "decode-sll.h"
 
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
 
#ifdef HAVE_LINUX_ETHTOOL_H
#include <linux/types.h>
#include <linux/ethtool.h>
#ifdef HAVE_LINUX_SOCKIOS_H
#include <linux/sockios.h>
#else
#error "ethtool.h present but sockios.h is missing"
#endif /* HAVE_LINUX_SOCKIOS_H */
#endif /* HAVE_LINUX_ETHTOOL_H */
 
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
 
#ifdef OS_WIN32
#include "win32-syscall.h"
#endif
 
/**
 * \brief output a majorant of hardware header length
 *
 * \param Name of a network interface
 */
static int GetIfaceMaxHWHeaderLength(const char *dev)
{
    if ((!strcmp("eth", dev)) || (!strcmp("br", dev)) || (!strcmp("bond", dev)) ||
            (!strcmp("wlan", dev)) || (!strcmp("tun", dev)) || (!strcmp("tap", dev)) ||
            (!strcmp("lo", dev))) {
        /* Add possible VLAN tag or Qing headers */
        return 8 + ETHERNET_HEADER_LEN;
    }
 
    if (!strcmp("ppp", dev))
        return SLL_HEADER_LEN;
    /* SLL_HEADER_LEN is the biggest one and
       add possible VLAN tag and Qing headers */
    return 8 + SLL_HEADER_LEN;
}
 
 
/**
 * \brief output the link MTU
 *
 * \param Name of link
 * \retval -1 in case of error, 0 if MTU can not be found
 */
int GetIfaceMTU(const char *dev)
{
#if defined SIOCGIFMTU
    struct ifreq ifr;
    int fd;
 
    (void)strlcpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd == -1) {
        return -1;
    }
 
    if (ioctl(fd, SIOCGIFMTU, (char *)&ifr) < 0) {
        SCLogWarning("Failure when trying to get MTU via ioctl for '%s': %s (%d)", dev,
                strerror(errno), errno);
        close(fd);
        return -1;
    }
    close(fd);
    SCLogInfo("%s: MTU %d", dev, ifr.ifr_mtu);
    return ifr.ifr_mtu;
#elif defined OS_WIN32
    return GetIfaceMTUWin32(dev);
#else
    /* ioctl is not defined, let's pretend returning 0 is ok */
    return 0;
#endif
}
 
/**
 * \brief output max packet size for a link
 *
 * This does a best effort to find the maximum packet size
 * for the link. In case of uncertainty, it will output a
 * majorant to be sure avoid the cost of dynamic allocation.
 *
 * \param LiveDevice object
 * \retval 0 in case of error
 */
int GetIfaceMaxPacketSize(LiveDevice *ld)
{
    if (ld == NULL)
        return 0;
 
    const char *dev = ld->dev;
    if ((dev == NULL) || strlen(dev) == 0)
        return 0;
 
    int mtu = ld->mtu;
    if (ld->mtu == 0) {
        mtu = GetIfaceMTU(dev);
        switch (mtu) {
            case 0:
            case -1:
                return 0;
        }
        ld->mtu = mtu;
    }
    int ll_header = GetIfaceMaxHWHeaderLength(dev);
    return ll_header + mtu;
}
 
#ifdef SIOCGIFFLAGS
/**
 * \brief Get interface flags.
 * \param ifname Interface name.
 * \return Interface flags or -1 on error
 */
int GetIfaceFlags(const char *ifname)
{
    struct ifreq ifr;
 
    int fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd < 0) {
        return -1;
    }
 
    memset(&ifr, 0, sizeof(ifr));
    strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 
    if (ioctl(fd, SIOCGIFFLAGS, &ifr) == -1) {
        SCLogError("%s: failed to get device flags: %s", ifname, strerror(errno));
        close(fd);
        return -1;
    }
 
    close(fd);
#ifdef OS_FREEBSD
    int flags = (ifr.ifr_flags & 0xffff) | (ifr.ifr_flagshigh << 16);
    return flags;
#else
    return ifr.ifr_flags;
#endif
}
#endif
 
#ifdef SIOCSIFFLAGS
/**
 * \brief Set interface flags.
 * \param ifname Interface name.
 * \param flags Flags to set.
 * \return Zero on success.
 */
int SetIfaceFlags(const char *ifname, int flags)
{
    struct ifreq ifr;
 
    int fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd < 0) {
        return -1;
    }
 
    memset(&ifr, 0, sizeof(ifr));
    strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
#ifdef OS_FREEBSD
    ifr.ifr_flags = flags & 0xffff;
    ifr.ifr_flagshigh = flags >> 16;
#else
    ifr.ifr_flags = (uint16_t)flags;
#endif
 
    if (ioctl(fd, SIOCSIFFLAGS, &ifr) == -1) {
        SCLogError("%s: unable to set device flags: %s", ifname, strerror(errno));
        close(fd);
        return -1;
    }
 
    close(fd);
    return 0;
}
#endif /* SIOCGIFFLAGS */
 
#ifdef SIOCGIFCAP
int GetIfaceCaps(const char *ifname)
{
    struct ifreq ifr;
 
    int fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd < 0) {
        return -1;
    }
 
    memset(&ifr, 0, sizeof(ifr));
    strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 
    if (ioctl(fd, SIOCGIFCAP, &ifr) == -1) {
        SCLogError("%s: unable to get device caps: %s", ifname, strerror(errno));
        close(fd);
        return -1;
    }
 
    close(fd);
    return ifr.ifr_curcap;
}
#endif
#ifdef SIOCSIFCAP
int SetIfaceCaps(const char *ifname, int caps)
{
    struct ifreq ifr;
 
    int fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd < 0) {
        return -1;
    }
 
    memset(&ifr, 0, sizeof(ifr));
    strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
    ifr.ifr_reqcap = caps;
 
    if (ioctl(fd, SIOCSIFCAP, &ifr) == -1) {
        SCLogError("%s: unable to set caps: %s", ifname, strerror(errno));
        close(fd);
        return -1;
    }
 
    close(fd);
    return 0;
}
#endif
 
 
#if defined HAVE_LINUX_ETHTOOL_H && defined SIOCETHTOOL
static int GetEthtoolValue(const char *dev, int cmd, uint32_t *value)
{
    struct ifreq ifr;
    int fd;
    struct ethtool_value ethv;
 
    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd == -1) {
        return -1;
    }
    (void)strlcpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
 
    ethv.cmd = cmd;
    ifr.ifr_data = (void *) &ethv;
    if (ioctl(fd, SIOCETHTOOL, (char *)&ifr) < 0) {
        SCLogWarning("%s: failed to get SIOCETHTOOL ioctl: %s", dev, strerror(errno));
        close(fd);
        return -1;
    }
 
    *value = ethv.data;
    close(fd);
    return 0;
}
 
static int SetEthtoolValue(const char *dev, int cmd, uint32_t value)
{
    struct ifreq ifr;
    int fd;
    struct ethtool_value ethv;
 
    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd == -1) {
        return -1;
    }
    (void)strlcpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
 
    ethv.cmd = cmd;
    ethv.data = value;
    ifr.ifr_data = (void *) &ethv;
    if (ioctl(fd, SIOCETHTOOL, (char *)&ifr) < 0) {
        SCLogWarning("%s: failed to set SIOCETHTOOL ioctl: %s", dev, strerror(errno));
        close(fd);
        return -1;
    }
 
    close(fd);
    return 0;
}
 
static int GetIfaceOffloadingLinux(const char *dev, int csum, int other)
{
    int ret = 0;
    uint32_t value = 0;
 
    if (csum) {
        const char *rx = "unset", *tx = "unset";
        int csum_ret = 0;
#ifdef ETHTOOL_GRXCSUM
        if (GetEthtoolValue(dev, ETHTOOL_GRXCSUM, &value) == 0 && value != 0) {
            rx = "SET";
            csum_ret = 1;
        }
#endif
#ifdef ETHTOOL_GTXCSUM
        if (GetEthtoolValue(dev, ETHTOOL_GTXCSUM, &value) == 0 && value != 0) {
            tx = "SET";
            csum_ret = 1;
        }
#endif
        if (csum_ret == 0)
            SCLogPerf("%s: NIC offloading: RX %s TX %s", dev, rx, tx);
        else {
            SCLogWarning("%s: NIC offloading: RX %s TX %s. Run: ethtool -K %s rx off tx off", dev,
                    rx, tx, dev);
            ret = 1;
        }
    }
 
    if (other) {
        const char *lro = "unset", *gro = "unset", *tso = "unset", *gso = "unset";
        const char *sg = "unset";
        int other_ret = 0;
#ifdef ETHTOOL_GGRO
        if (GetEthtoolValue(dev, ETHTOOL_GGRO, &value) == 0 && value != 0) {
            gro = "SET";
            other_ret = 1;
        }
#endif
#ifdef ETHTOOL_GTSO
        if (GetEthtoolValue(dev, ETHTOOL_GTSO, &value) == 0 && value != 0) {
            tso = "SET";
            other_ret = 1;
        }
#endif
#ifdef ETHTOOL_GGSO
        if (GetEthtoolValue(dev, ETHTOOL_GGSO, &value) == 0 && value != 0) {
            gso = "SET";
            other_ret = 1;
        }
#endif
#ifdef ETHTOOL_GSG
        if (GetEthtoolValue(dev, ETHTOOL_GSG, &value) == 0 && value != 0) {
            sg = "SET";
            other_ret = 1;
        }
#endif
#ifdef ETHTOOL_GFLAGS
        if (GetEthtoolValue(dev, ETHTOOL_GFLAGS, &value) == 0) {
            if (value & ETH_FLAG_LRO) {
                lro = "SET";
                other_ret = 1;
            }
        }
#endif
        if (other_ret == 0) {
            SCLogPerf("%s: NIC offloading: SG: %s, GRO: %s, LRO: %s, TSO: %s, GSO: %s", dev, sg,
                    gro, lro, tso, gso);
        } else {
            SCLogWarning("%s: NIC offloading: SG: %s, GRO: %s, LRO: %s, TSO: %s, GSO: %s. Run: "
                         "ethtool -K %s sg off gro off lro off tso off gso off",
                    dev, sg, gro, lro, tso, gso, dev);
            ret = 1;
        }
    }
    return ret;
}
 
static int DisableIfaceOffloadingLinux(LiveDevice *ldev, int csum, int other)
{
    int ret = 0;
    uint32_t value = 0;
 
    if (ldev == NULL)
        return -1;
 
    const char *dev = ldev->dev;
 
    if (csum) {
#ifdef ETHTOOL_GRXCSUM
        if (GetEthtoolValue(dev, ETHTOOL_GRXCSUM, &value) == 0 && value != 0) {
            SCLogPerf("%s: disabling rxcsum offloading", dev);
            SetEthtoolValue(dev, ETHTOOL_SRXCSUM, 0);
            ldev->offload_orig |= OFFLOAD_FLAG_RXCSUM;
        }
#endif
#ifdef ETHTOOL_GTXCSUM
        if (GetEthtoolValue(dev, ETHTOOL_GTXCSUM, &value) == 0 && value != 0) {
            SCLogPerf("%s: disabling txcsum offloading", dev);
            SetEthtoolValue(dev, ETHTOOL_STXCSUM, 0);
            ldev->offload_orig |= OFFLOAD_FLAG_TXCSUM;
        }
#endif
    }
    if (other) {
#ifdef ETHTOOL_GGRO
        if (GetEthtoolValue(dev, ETHTOOL_GGRO, &value) == 0 && value != 0) {
            SCLogPerf("%s: disabling gro offloading", dev);
            SetEthtoolValue(dev, ETHTOOL_SGRO, 0);
            ldev->offload_orig |= OFFLOAD_FLAG_GRO;
        }
#endif
#ifdef ETHTOOL_GTSO
        if (GetEthtoolValue(dev, ETHTOOL_GTSO, &value) == 0 && value != 0) {
            SCLogPerf("%s: disabling tso offloading", dev);
            SetEthtoolValue(dev, ETHTOOL_STSO, 0);
            ldev->offload_orig |= OFFLOAD_FLAG_TSO;
        }
#endif
#ifdef ETHTOOL_GGSO
        if (GetEthtoolValue(dev, ETHTOOL_GGSO, &value) == 0 && value != 0) {
            SCLogPerf("%s: disabling gso offloading", dev);
            SetEthtoolValue(dev, ETHTOOL_SGSO, 0);
            ldev->offload_orig |= OFFLOAD_FLAG_GSO;
        }
#endif
#ifdef ETHTOOL_GSG
        if (GetEthtoolValue(dev, ETHTOOL_GSG, &value) == 0 && value != 0) {
            SCLogPerf("%s: disabling sg offloading", dev);
            SetEthtoolValue(dev, ETHTOOL_SSG, 0);
            ldev->offload_orig |= OFFLOAD_FLAG_SG;
        }
#endif
#ifdef ETHTOOL_GFLAGS
        if (GetEthtoolValue(dev, ETHTOOL_GFLAGS, &value) == 0) {
            if (value & ETH_FLAG_LRO) {
                SCLogPerf("%s: disabling lro offloading", dev);
                SetEthtoolValue(dev, ETHTOOL_SFLAGS, value & ~ETH_FLAG_LRO);
                ldev->offload_orig |= OFFLOAD_FLAG_LRO;
            }
        }
#endif
    }
    return ret;
}
 
static int RestoreIfaceOffloadingLinux(LiveDevice *ldev)
{
    if (ldev == NULL)
        return -1;
 
    const char *dev = ldev->dev;
 
#ifdef ETHTOOL_GRXCSUM
    if (ldev->offload_orig & OFFLOAD_FLAG_RXCSUM) {
        SCLogPerf("%s: restoring rxcsum offloading", dev);
        SetEthtoolValue(dev, ETHTOOL_SRXCSUM, 1);
    }
#endif
#ifdef ETHTOOL_GTXCSUM
    if (ldev->offload_orig & OFFLOAD_FLAG_TXCSUM) {
        SCLogPerf("%s: restoring txcsum offloading", dev);
        SetEthtoolValue(dev, ETHTOOL_STXCSUM, 1);
    }
#endif
#ifdef ETHTOOL_GGRO
    if (ldev->offload_orig & OFFLOAD_FLAG_GRO) {
        SCLogPerf("%s: restoring gro offloading", dev);
        SetEthtoolValue(dev, ETHTOOL_SGRO, 1);
    }
#endif
#ifdef ETHTOOL_GTSO
    if (ldev->offload_orig & OFFLOAD_FLAG_TSO) {
        SCLogPerf("%s: restoring tso offloading", dev);
        SetEthtoolValue(dev, ETHTOOL_STSO, 1);
    }
#endif
#ifdef ETHTOOL_GGSO
    if (ldev->offload_orig & OFFLOAD_FLAG_GSO) {
        SCLogPerf("%s: restoring gso offloading", dev);
        SetEthtoolValue(dev, ETHTOOL_SGSO, 1);
    }
#endif
#ifdef ETHTOOL_GSG
    if (ldev->offload_orig & OFFLOAD_FLAG_SG) {
        SCLogPerf("%s: restoring sg offloading", dev);
        SetEthtoolValue(dev, ETHTOOL_SSG, 1);
    }
#endif
#ifdef ETHTOOL_GFLAGS
    if (ldev->offload_orig & OFFLOAD_FLAG_LRO) {
        uint32_t value = 0;
        if (GetEthtoolValue(dev, ETHTOOL_GFLAGS, &value) == 0) {
            SCLogPerf("%s: restoring lro offloading", dev);
            SetEthtoolValue(dev, ETHTOOL_SFLAGS, value & ETH_FLAG_LRO);
        }
    }
#endif
    return 0;
}
 
#endif /* defined HAVE_LINUX_ETHTOOL_H && defined SIOCETHTOOL */
 
#ifdef SIOCGIFCAP
static int GetIfaceOffloadingBSD(const char *ifname)
{
    int ret = 0;
    int if_caps = GetIfaceCaps(ifname);
    if (if_caps == -1) {
        return -1;
    }
    SCLogDebug("if_caps %X", if_caps);
 
    if (if_caps & IFCAP_RXCSUM) {
        SCLogWarning("%s: RXCSUM activated can lead to capture problems. Run: ifconfig %s -rxcsum",
                ifname, ifname);
        ret = 1;
    }
#ifdef IFCAP_TOE
    if (if_caps & (IFCAP_TSO|IFCAP_TOE|IFCAP_LRO)) {
        SCLogWarning("%s: TSO, TOE or LRO activated can lead to capture problems. Run: ifconfig %s "
                     "-tso -toe -lro",
                ifname, ifname);
        ret = 1;
    }
#else
    if (if_caps & (IFCAP_TSO|IFCAP_LRO)) {
        SCLogWarning(
                "%s: TSO or LRO activated can lead to capture problems. Run: ifconfig %s -tso -lro",
                ifname, ifname);
        ret = 1;
    }
#endif
    return ret;
}
#endif
 
#ifdef SIOCSIFCAP
static int DisableIfaceOffloadingBSD(LiveDevice *ldev)
{
    int ret = 0;
 
    if (ldev == NULL)
        return -1;
 
    const char *ifname = ldev->dev;
    int if_caps = GetIfaceCaps(ifname);
    int set_caps = if_caps;
    if (if_caps == -1) {
        return -1;
    }
    SCLogDebug("if_caps %X", if_caps);
 
    if (if_caps & IFCAP_RXCSUM) {
        SCLogPerf("%s: disabling rxcsum offloading", ifname);
        set_caps &= ~IFCAP_RXCSUM;
    }
    if (if_caps & IFCAP_TXCSUM) {
        SCLogPerf("%s: disabling txcsum offloading", ifname);
        set_caps &= ~IFCAP_TXCSUM;
    }
#ifdef IFCAP_RXCSUM_IPV6
    if (if_caps & IFCAP_RXCSUM_IPV6) {
        SCLogPerf("%s: disabling rxcsum6 offloading", ifname);
        set_caps &= ~IFCAP_RXCSUM_IPV6;
    }
#endif
#ifdef IFCAP_TXCSUM_IPV6
    if (if_caps & IFCAP_TXCSUM_IPV6) {
        SCLogPerf("%s: disabling txcsum6 offloading", ifname);
        set_caps &= ~IFCAP_TXCSUM_IPV6;
    }
#endif
#ifdef IFCAP_TOE
    if (if_caps & (IFCAP_TSO|IFCAP_TOE|IFCAP_LRO)) {
        SCLogPerf("%s: disabling tso|toe|lro offloading", ifname);
        set_caps &= ~(IFCAP_TSO|IFCAP_LRO);
    }
#else
    if (if_caps & (IFCAP_TSO|IFCAP_LRO)) {
        SCLogPerf("%s: disabling tso|lro offloading", ifname);
        set_caps &= ~(IFCAP_TSO|IFCAP_LRO);
    }
#endif
    if (set_caps != if_caps) {
        if (if_caps & IFCAP_RXCSUM)
            ldev->offload_orig |= OFFLOAD_FLAG_RXCSUM;
        if (if_caps & IFCAP_TSO)
            ldev->offload_orig |= OFFLOAD_FLAG_TSO;
#ifdef IFCAP_TOE
        if (if_caps & IFCAP_TOE)
            ldev->offload_orig |= OFFLOAD_FLAG_TOE;
#endif
        if (if_caps & IFCAP_LRO)
            ldev->offload_orig |= OFFLOAD_FLAG_LRO;
 
        SetIfaceCaps(ifname, set_caps);
    }
    return ret;
}
 
static int RestoreIfaceOffloadingBSD(LiveDevice *ldev)
{
    int ret = 0;
 
    if (ldev == NULL)
        return -1;
 
    const char *ifname = ldev->dev;
    int if_caps = GetIfaceCaps(ifname);
    int set_caps = if_caps;
    if (if_caps == -1) {
        return -1;
    }
    SCLogDebug("if_caps %X", if_caps);
 
    if (ldev->offload_orig & OFFLOAD_FLAG_RXCSUM) {
        SCLogPerf("%s: restoring rxcsum offloading", ifname);
        set_caps |= IFCAP_RXCSUM;
    }
    if (ldev->offload_orig & OFFLOAD_FLAG_TSO) {
        SCLogPerf("%s: restoring tso offloading", ifname);
        set_caps |= IFCAP_TSO;
    }
#ifdef IFCAP_TOE
    if (ldev->offload_orig & OFFLOAD_FLAG_TOE) {
        SCLogPerf("%s: restoring toe offloading", ifname);
        set_caps |= IFCAP_TOE;
    }
#endif
    if (ldev->offload_orig & OFFLOAD_FLAG_LRO) {
        SCLogPerf("%s: restoring lro offloading", ifname);
        set_caps |= IFCAP_LRO;
    }
 
    if (set_caps != if_caps) {
        SetIfaceCaps(ifname, set_caps);
    }
    return ret;
}
#endif
 
/**
 * \brief output offloading status of the link
 *
 * Test interface for offloading features. If one of them is
 * activated then suricata mays received packets merge at reception.
 * The result is oversized packets and this may cause some serious
 * problem in some capture mode where the size of the packet is
 * limited (AF_PACKET in V2 more for example).
 *
 * \param Name of link
 * \param csum check if checksums are offloaded
 * \param other check if other things are offloaded: TSO, GRO, etc.
 * \retval -1 in case of error, 0 if none, 1 if some
 */
int GetIfaceOffloading(const char *dev, int csum, int other)
{
#if defined HAVE_LINUX_ETHTOOL_H && defined SIOCETHTOOL
    return GetIfaceOffloadingLinux(dev, csum, other);
#elif defined SIOCGIFCAP
    return GetIfaceOffloadingBSD(dev);
#elif defined OS_WIN32
    return GetIfaceOffloadingWin32(dev, csum, other);
#else
    return 0;
#endif
}
 
int DisableIfaceOffloading(LiveDevice *dev, int csum, int other)
{
    /* already set */
    if (dev->offload_orig != 0)
        return 0;
#if defined HAVE_LINUX_ETHTOOL_H && defined SIOCETHTOOL
    return DisableIfaceOffloadingLinux(dev, csum, other);
#elif defined SIOCSIFCAP
    return DisableIfaceOffloadingBSD(dev);
#elif defined OS_WIN32
    return DisableIfaceOffloadingWin32(dev, csum, other);
#else
    return 0;
#endif
 
}
 
void RestoreIfaceOffloading(LiveDevice *dev)
{
    if (dev->offload_orig != 0) {
#if defined HAVE_LINUX_ETHTOOL_H && defined SIOCETHTOOL
        RestoreIfaceOffloadingLinux(dev);
#elif defined SIOCSIFCAP
        RestoreIfaceOffloadingBSD(dev);
#elif defined OS_WIN32
        RestoreIfaceOffloadingWin32(dev);
#endif
    }
}
 
int GetIfaceRSSQueuesNum(const char *dev)
{
#if defined HAVE_LINUX_ETHTOOL_H && defined ETHTOOL_GRXRINGS
    struct ifreq ifr;
    struct ethtool_rxnfc nfccmd;
    int fd;
 
    (void)strlcpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd == -1) {
        SCLogWarning("%s: failed to open socket for ioctl: %s", dev, strerror(errno));
        return -1;
    }
 
    nfccmd.cmd = ETHTOOL_GRXRINGS;
    ifr.ifr_data = (void*) &nfccmd;
 
    if (ioctl(fd, SIOCETHTOOL, (char *)&ifr) < 0) {
        if (errno != ENOTSUP) {
            SCLogWarning("%s: failed get number of RSS queue ioctl: %s", dev, strerror(errno));
        }
        close(fd);
        return 0;
    }
    close(fd);
    SCLogInfo("%s: RX RSS queues: %d", dev, (int)nfccmd.data);
    return (int)nfccmd.data;
#else
    return 0;
#endif
}