/* SPDX-License-Identifier: LGPL-2.1+ */

#include <net/if.h>
#include <sys/ioctl.h>
#include <linux/ethtool.h>
#include <linux/netdevice.h>
#include <linux/sockios.h>

#include "conf-parser.h"
#include "ethtool-util.h"
#include "extract-word.h"
#include "fd-util.h"
#include "log.h"
#include "memory-util.h"
#include "socket-util.h"
#include "string-table.h"
#include "strxcpyx.h"

static const char* const duplex_table[_DUP_MAX] = {
        [DUP_FULL] = "full",
        [DUP_HALF] = "half"
};

DEFINE_STRING_TABLE_LOOKUP(duplex, Duplex);
DEFINE_CONFIG_PARSE_ENUM(config_parse_duplex, duplex, Duplex, "Failed to parse duplex setting");

static const char* const wol_table[_WOL_MAX] = {
        [WOL_PHY]         = "phy",
        [WOL_UCAST]       = "unicast",
        [WOL_MCAST]       = "multicast",
        [WOL_BCAST]       = "broadcast",
        [WOL_ARP]         = "arp",
        [WOL_MAGIC]       = "magic",
        [WOL_MAGICSECURE] = "secureon",
        [WOL_OFF]         = "off",
};

DEFINE_STRING_TABLE_LOOKUP(wol, WakeOnLan);
DEFINE_CONFIG_PARSE_ENUM(config_parse_wol, wol, WakeOnLan, "Failed to parse WakeOnLan setting");

static const char* const port_table[] = {
        [NET_DEV_PORT_TP]     = "tp",
        [NET_DEV_PORT_AUI]    = "aui",
        [NET_DEV_PORT_MII]    = "mii",
        [NET_DEV_PORT_FIBRE]  = "fibre",
        [NET_DEV_PORT_BNC]    = "bnc",
};

DEFINE_STRING_TABLE_LOOKUP(port, NetDevPort);
DEFINE_CONFIG_PARSE_ENUM(config_parse_port, port, NetDevPort, "Failed to parse Port setting");

static const char* const netdev_feature_table[_NET_DEV_FEAT_MAX] = {
        [NET_DEV_FEAT_RX]   = "rx-checksum",
        [NET_DEV_FEAT_TX]   = "tx-checksum-", /* The suffix "-" means any feature beginning with "tx-checksum-" */
        [NET_DEV_FEAT_GSO]  = "tx-generic-segmentation",
        [NET_DEV_FEAT_GRO]  = "rx-gro",
        [NET_DEV_FEAT_LRO]  = "rx-lro",
        [NET_DEV_FEAT_TSO]  = "tx-tcp-segmentation",
        [NET_DEV_FEAT_TSO6] = "tx-tcp6-segmentation",
};

static const char* const ethtool_link_mode_bit_table[] = {
        [ETHTOOL_LINK_MODE_10baseT_Half_BIT]               = "10baset-half",
        [ETHTOOL_LINK_MODE_10baseT_Full_BIT]               = "10baset-full",
        [ETHTOOL_LINK_MODE_100baseT_Half_BIT]              = "100baset-half",
        [ETHTOOL_LINK_MODE_100baseT_Full_BIT]              = "100baset-full",
        [ETHTOOL_LINK_MODE_1000baseT_Half_BIT]             = "1000baset-half",
        [ETHTOOL_LINK_MODE_1000baseT_Full_BIT]             = "1000baset-full",
        [ETHTOOL_LINK_MODE_Autoneg_BIT]                    = "autonegotiation",
        [ETHTOOL_LINK_MODE_TP_BIT]                         = "tp",
        [ETHTOOL_LINK_MODE_AUI_BIT]                        = "aui",
        [ETHTOOL_LINK_MODE_MII_BIT]                        = "mii",
        [ETHTOOL_LINK_MODE_FIBRE_BIT]                      = "fibre",
        [ETHTOOL_LINK_MODE_BNC_BIT]                        = "bnc",
        [ETHTOOL_LINK_MODE_10000baseT_Full_BIT]            = "10000baset-full",
        [ETHTOOL_LINK_MODE_Pause_BIT]                      = "pause",
        [ETHTOOL_LINK_MODE_Asym_Pause_BIT]                 = "asym-pause",
        [ETHTOOL_LINK_MODE_2500baseX_Full_BIT]             = "2500basex-full",
        [ETHTOOL_LINK_MODE_Backplane_BIT]                  = "backplane",
        [ETHTOOL_LINK_MODE_1000baseKX_Full_BIT]            = "1000basekx-full",
        [ETHTOOL_LINK_MODE_10000baseKX4_Full_BIT]          = "10000basekx4-full",
        [ETHTOOL_LINK_MODE_10000baseKR_Full_BIT]           = "10000basekr-full",
        [ETHTOOL_LINK_MODE_10000baseR_FEC_BIT]             = "10000baser-fec",
        [ETHTOOL_LINK_MODE_20000baseMLD2_Full_BIT]         = "20000basemld2-full",
        [ETHTOOL_LINK_MODE_20000baseKR2_Full_BIT]          = "20000basekr2-full",
        [ETHTOOL_LINK_MODE_40000baseKR4_Full_BIT]          = "40000basekr4-full",
        [ETHTOOL_LINK_MODE_40000baseCR4_Full_BIT]          = "40000basecr4-full",
        [ETHTOOL_LINK_MODE_40000baseSR4_Full_BIT]          = "40000basesr4-full",
        [ETHTOOL_LINK_MODE_40000baseLR4_Full_BIT]          = "40000baselr4-full",
        [ETHTOOL_LINK_MODE_56000baseKR4_Full_BIT]          = "56000basekr4-full",
        [ETHTOOL_LINK_MODE_56000baseCR4_Full_BIT]          = "56000basecr4-full",
        [ETHTOOL_LINK_MODE_56000baseSR4_Full_BIT]          = "56000basesr4-full",
        [ETHTOOL_LINK_MODE_56000baseLR4_Full_BIT]          = "56000baselr4-full",
        [ETHTOOL_LINK_MODE_25000baseCR_Full_BIT]           = "25000basecr-full",
        [ETHTOOL_LINK_MODE_25000baseKR_Full_BIT]           = "25000basekr-full",
        [ETHTOOL_LINK_MODE_25000baseSR_Full_BIT]           = "25000basesr-full",
        [ETHTOOL_LINK_MODE_50000baseCR2_Full_BIT]          = "50000basecr2-full",
        [ETHTOOL_LINK_MODE_50000baseKR2_Full_BIT]          = "50000basekr2-full",
        [ETHTOOL_LINK_MODE_100000baseKR4_Full_BIT]         = "100000basekr4-full",
        [ETHTOOL_LINK_MODE_100000baseSR4_Full_BIT]         = "100000basesr4-full",
        [ETHTOOL_LINK_MODE_100000baseCR4_Full_BIT]         = "100000basecr4-full",
        [ETHTOOL_LINK_MODE_100000baseLR4_ER4_Full_BIT]     = "100000baselr4-er4-full",
        [ETHTOOL_LINK_MODE_50000baseSR2_Full_BIT]          = "50000basesr2-full",
        [ETHTOOL_LINK_MODE_1000baseX_Full_BIT]             = "1000basex-full",
        [ETHTOOL_LINK_MODE_10000baseCR_Full_BIT]           = "10000basecr-full",
        [ETHTOOL_LINK_MODE_10000baseSR_Full_BIT]           = "10000basesr-full",
        [ETHTOOL_LINK_MODE_10000baseLR_Full_BIT]           = "10000baselr-full",
        [ETHTOOL_LINK_MODE_10000baseLRM_Full_BIT]          = "10000baselrm-full",
        [ETHTOOL_LINK_MODE_10000baseER_Full_BIT]           = "10000baseer-full",
        [ETHTOOL_LINK_MODE_2500baseT_Full_BIT]             = "2500baset-full",
        [ETHTOOL_LINK_MODE_5000baseT_Full_BIT]             = "5000baset-full",
        [ETHTOOL_LINK_MODE_FEC_NONE_BIT]                   = "fec-none",
        [ETHTOOL_LINK_MODE_FEC_RS_BIT]                     = "fec-rs",
        [ETHTOOL_LINK_MODE_FEC_BASER_BIT]                  = "fec-baser",
        [ETHTOOL_LINK_MODE_50000baseKR_Full_BIT]           = "50000basekr_full",
        [ETHTOOL_LINK_MODE_50000baseSR_Full_BIT]           = "50000basesr_full",
        [ETHTOOL_LINK_MODE_50000baseCR_Full_BIT]           = "50000basecr_full",
        [ETHTOOL_LINK_MODE_50000baseLR_ER_FR_Full_BIT]     = "50000baselr_er_fr_full",
        [ETHTOOL_LINK_MODE_50000baseDR_Full_BIT]           = "50000basedr_full",
        [ETHTOOL_LINK_MODE_100000baseKR2_Full_BIT]         = "100000basekr2_full",
        [ETHTOOL_LINK_MODE_100000baseSR2_Full_BIT]         = "100000basesr2_full",
        [ETHTOOL_LINK_MODE_100000baseCR2_Full_BIT]         = "100000basecr2_full",
        [ETHTOOL_LINK_MODE_100000baseLR2_ER2_FR2_Full_BIT] = "100000baselr2_er2_fr2_full",
        [ETHTOOL_LINK_MODE_100000baseDR2_Full_BIT]         = "100000basedr2_full",
        [ETHTOOL_LINK_MODE_200000baseKR4_Full_BIT]         = "200000basekr4_full",
        [ETHTOOL_LINK_MODE_200000baseSR4_Full_BIT]         = "200000basesr4_full",
        [ETHTOOL_LINK_MODE_200000baseCR4_Full_BIT]         = "200000basecr4_full",
        [ETHTOOL_LINK_MODE_200000baseLR4_ER4_FR4_Full_BIT] = "200000baselr4_er4_fr4_full",
        [ETHTOOL_LINK_MODE_200000baseDR4_Full_BIT]         = "200000basedr4_full",
};
/* Make sure the array is large enough to fit all bits */
assert_cc((ELEMENTSOF(ethtool_link_mode_bit_table)-1) / 32 < N_ADVERTISE);

DEFINE_STRING_TABLE_LOOKUP(ethtool_link_mode_bit, enum ethtool_link_mode_bit_indices);

static int ethtool_connect_or_warn(int *ret, bool warn) {
        int fd;

        assert_return(ret, -EINVAL);

        fd = socket_ioctl_fd();
        if (fd < 0)
                return log_full_errno(warn ? LOG_WARNING: LOG_DEBUG, fd,
                                       "ethtool: could not create control socket: %m");

        *ret = fd;

        return 0;
}

int ethtool_get_driver(int *ethtool_fd, const char *ifname, char **ret) {
        struct ethtool_drvinfo ecmd = {
                .cmd = ETHTOOL_GDRVINFO
        };
        struct ifreq ifr = {
                .ifr_data = (void*) &ecmd
        };
        char *d;
        int r;

        if (*ethtool_fd < 0) {
                r = ethtool_connect_or_warn(ethtool_fd, true);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return -errno;

        if (isempty(ecmd.driver))
                return -ENODATA;

        d = strdup(ecmd.driver);
        if (!d)
                return -ENOMEM;

        *ret = d;
        return 0;
}

int ethtool_get_link_info(int *ethtool_fd, const char *ifname,
                          int *ret_autonegotiation, uint64_t *ret_speed,
                          Duplex *ret_duplex, NetDevPort *ret_port) {
        struct ethtool_cmd ecmd = {
                .cmd = ETHTOOL_GSET,
        };
        struct ifreq ifr = {
                .ifr_data = (void*) &ecmd,
        };
        int r;

        if (*ethtool_fd < 0) {
                r = ethtool_connect_or_warn(ethtool_fd, false);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return -errno;

        if (ret_autonegotiation)
                *ret_autonegotiation = ecmd.autoneg;

        if (ret_speed) {
                uint32_t speed;

                speed = ethtool_cmd_speed(&ecmd);
                *ret_speed = speed == (uint32_t) SPEED_UNKNOWN ?
                        UINT64_MAX : (uint64_t) speed * 1000 * 1000;
        }

        if (ret_duplex)
                *ret_duplex = ecmd.duplex;

        if (ret_port)
                *ret_port = ecmd.port;

        return 0;
}

int ethtool_get_permanent_macaddr(int *ethtool_fd, const char *ifname, struct ether_addr *ret) {
        _cleanup_close_ int fd = -1;
        struct {
                struct ethtool_perm_addr addr;
                uint8_t space[MAX_ADDR_LEN];
        } epaddr = {
                .addr.cmd = ETHTOOL_GPERMADDR,
                .addr.size = MAX_ADDR_LEN,
        };
        struct ifreq ifr = {
                .ifr_data = (caddr_t) &epaddr,
        };
        int r;

        assert(ifname);
        assert(ret);

        if (!ethtool_fd)
                ethtool_fd = &fd;

        if (*ethtool_fd < 0) {
                r = ethtool_connect_or_warn(ethtool_fd, false);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return -errno;

        if (epaddr.addr.size != 6)
                return -EOPNOTSUPP;

#pragma GCC diagnostic push
#if HAVE_ZERO_LENGTH_BOUNDS
#  pragma GCC diagnostic ignored "-Wzero-length-bounds"
#endif
        for (size_t i = 0; i < epaddr.addr.size; i++)
                ret->ether_addr_octet[i] = epaddr.addr.data[i];
#pragma GCC diagnostic pop

        return 0;
}

int ethtool_set_speed(int *ethtool_fd, const char *ifname, unsigned speed, Duplex duplex) {
        struct ethtool_cmd ecmd = {
                .cmd = ETHTOOL_GSET
        };
        struct ifreq ifr = {
                .ifr_data = (void*) &ecmd
        };
        bool need_update = false;
        int r;

        if (speed == 0 && duplex == _DUP_INVALID)
                return 0;

        if (*ethtool_fd < 0) {
                r = ethtool_connect_or_warn(ethtool_fd, true);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return -errno;

        if (ethtool_cmd_speed(&ecmd) != speed) {
                ethtool_cmd_speed_set(&ecmd, speed);
                need_update = true;
        }

        switch (duplex) {
                case DUP_HALF:
                        if (ecmd.duplex != DUPLEX_HALF) {
                                ecmd.duplex = DUPLEX_HALF;
                                need_update = true;
                        }
                        break;
                case DUP_FULL:
                        if (ecmd.duplex != DUPLEX_FULL) {
                                ecmd.duplex = DUPLEX_FULL;
                                need_update = true;
                        }
                        break;
                default:
                        break;
        }

        if (need_update) {
                ecmd.cmd = ETHTOOL_SSET;

                r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
                if (r < 0)
                        return -errno;
        }

        return 0;
}

int ethtool_set_wol(int *ethtool_fd, const char *ifname, WakeOnLan wol) {
        struct ethtool_wolinfo ecmd = {
                .cmd = ETHTOOL_GWOL
        };
        struct ifreq ifr = {
                .ifr_data = (void*) &ecmd
        };
        bool need_update = false;
        int r;

        if (wol == _WOL_INVALID)
                return 0;

        if (*ethtool_fd < 0) {
                r = ethtool_connect_or_warn(ethtool_fd, true);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return -errno;

        switch (wol) {
        case WOL_PHY:
                if (ecmd.wolopts != WAKE_PHY) {
                        ecmd.wolopts = WAKE_PHY;
                        need_update = true;
                }
                break;
        case WOL_UCAST:
                if (ecmd.wolopts != WAKE_UCAST) {
                        ecmd.wolopts = WAKE_UCAST;
                        need_update = true;
                }
                break;
        case WOL_MCAST:
                if (ecmd.wolopts != WAKE_MCAST) {
                        ecmd.wolopts = WAKE_MCAST;
                        need_update = true;
                }
                break;
        case WOL_BCAST:
                if (ecmd.wolopts != WAKE_BCAST) {
                        ecmd.wolopts = WAKE_BCAST;
                        need_update = true;
                }
                break;
        case WOL_ARP:
                if (ecmd.wolopts != WAKE_ARP) {
                        ecmd.wolopts = WAKE_ARP;
                        need_update = true;
                }
                break;
        case WOL_MAGIC:
                if (ecmd.wolopts != WAKE_MAGIC) {
                        ecmd.wolopts = WAKE_MAGIC;
                        need_update = true;
                }
                break;
        case WOL_MAGICSECURE:
                if (ecmd.wolopts != WAKE_MAGICSECURE) {
                        ecmd.wolopts = WAKE_MAGICSECURE;
                        need_update = true;
                }
                break;
        case WOL_OFF:
                if (ecmd.wolopts != 0) {
                        ecmd.wolopts = 0;
                        need_update = true;
                }
                break;
        default:
                break;
        }

        if (need_update) {
                ecmd.cmd = ETHTOOL_SWOL;

                r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
                if (r < 0)
                        return -errno;
        }

        return 0;
}

int ethtool_set_nic_buffer_size(int *ethtool_fd, const char *ifname, netdev_ring_param *ring) {
        struct ethtool_ringparam ecmd = {
                .cmd = ETHTOOL_GRINGPARAM
        };
        struct ifreq ifr = {
                .ifr_data = (void*) &ecmd
        };
        bool need_update = false;
        int r;

        if (*ethtool_fd < 0) {
                r = ethtool_connect_or_warn(ethtool_fd, true);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return -errno;

        if (ring->rx_pending_set && ecmd.rx_pending != ring->rx_pending) {
                ecmd.rx_pending = ring->rx_pending;
                need_update = true;
        }

        if (ring->rx_mini_pending_set && ecmd.rx_mini_pending != ring->rx_mini_pending) {
                ecmd.rx_mini_pending = ring->rx_mini_pending;
                need_update = true;
        }

        if (ring->rx_jumbo_pending_set && ecmd.rx_jumbo_pending != ring->rx_jumbo_pending) {
                ecmd.rx_jumbo_pending = ring->rx_jumbo_pending;
                need_update = true;
        }

        if (ring->tx_pending_set && ecmd.tx_pending != ring->tx_pending) {
                ecmd.tx_pending = ring->tx_pending;
                need_update = true;
        }

        if (need_update) {
                ecmd.cmd = ETHTOOL_SRINGPARAM;

                r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
                if (r < 0)
                        return -errno;
        }

        return 0;
}

static int get_stringset(int ethtool_fd, struct ifreq *ifr, int stringset_id, struct ethtool_gstrings **gstrings) {
        _cleanup_free_ struct ethtool_gstrings *strings = NULL;
        struct {
                struct ethtool_sset_info info;
                uint32_t space;
        } buffer = {
                .info = {
                        .cmd = ETHTOOL_GSSET_INFO,
                        .sset_mask = UINT64_C(1) << stringset_id,
                },
        };
        unsigned len;
        int r;

        ifr->ifr_data = (void *) &buffer.info;

        r = ioctl(ethtool_fd, SIOCETHTOOL, ifr);
        if (r < 0)
                return -errno;

        if (!buffer.info.sset_mask)
                return -EINVAL;

#pragma GCC diagnostic push
#if HAVE_ZERO_LENGTH_BOUNDS
#  pragma GCC diagnostic ignored "-Wzero-length-bounds"
#endif
        len = buffer.info.data[0];
#pragma GCC diagnostic pop

        strings = malloc0(sizeof(struct ethtool_gstrings) + len * ETH_GSTRING_LEN);
        if (!strings)
                return -ENOMEM;

        strings->cmd = ETHTOOL_GSTRINGS;
        strings->string_set = stringset_id;
        strings->len = len;

        ifr->ifr_data = (void *) strings;

        r = ioctl(ethtool_fd, SIOCETHTOOL, ifr);
        if (r < 0)
                return -errno;

        *gstrings = TAKE_PTR(strings);

        return 0;
}

static int set_features_bit(
                const struct ethtool_gstrings *strings,
                const char *feature,
                bool flag,
                struct ethtool_sfeatures *sfeatures) {
        bool found = false;

        assert(strings);
        assert(feature);
        assert(sfeatures);

        for (size_t i = 0; i < strings->len; i++)
                if (streq((char *) &strings->data[i * ETH_GSTRING_LEN], feature) ||
                    (endswith(feature, "-") && startswith((char *) &strings->data[i * ETH_GSTRING_LEN], feature))) {
                        size_t block, bit;

                        block = i / 32;
                        bit = i % 32;

                        sfeatures->features[block].valid |= 1 << bit;
                        SET_FLAG(sfeatures->features[block].requested, 1 << bit, flag);
                        found = true;
                }

        return found ? 0 : -ENODATA;
}

int ethtool_set_features(int *ethtool_fd, const char *ifname, int *features) {
        _cleanup_free_ struct ethtool_gstrings *strings = NULL;
        struct ethtool_sfeatures *sfeatures;
        struct ifreq ifr = {};
        int i, r;

        if (*ethtool_fd < 0) {
                r = ethtool_connect_or_warn(ethtool_fd, true);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = get_stringset(*ethtool_fd, &ifr, ETH_SS_FEATURES, &strings);
        if (r < 0)
                return log_warning_errno(r, "ethtool: could not get ethtool features for %s", ifname);

        sfeatures = alloca0(sizeof(struct ethtool_sfeatures) + DIV_ROUND_UP(strings->len, 32U) * sizeof(sfeatures->features[0]));
        sfeatures->cmd = ETHTOOL_SFEATURES;
        sfeatures->size = DIV_ROUND_UP(strings->len, 32U);

        for (i = 0; i < _NET_DEV_FEAT_MAX; i++)
                if (features[i] != -1) {
                        r = set_features_bit(strings, netdev_feature_table[i], features[i], sfeatures);
                        if (r < 0) {
                                log_warning_errno(r, "ethtool: could not find feature, ignoring: %s", netdev_feature_table[i]);
                                continue;
                        }
                }

        ifr.ifr_data = (void *) sfeatures;

        r = ioctl(*ethtool_fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return log_warning_errno(r, "ethtool: could not set ethtool features for %s", ifname);

        return 0;
}

static int get_glinksettings(int fd, struct ifreq *ifr, struct ethtool_link_usettings **g) {
        struct ecmd {
                struct ethtool_link_settings req;
                __u32 link_mode_data[3 * ETHTOOL_LINK_MODE_MASK_MAX_KERNEL_NU32];
        } ecmd = {
                .req.cmd = ETHTOOL_GLINKSETTINGS,
        };
        struct ethtool_link_usettings *u;
        unsigned offset;
        int r;

        /* The interaction user/kernel via the new API requires a small ETHTOOL_GLINKSETTINGS
           handshake first to agree on the length of the link mode bitmaps. If kernel doesn't
           agree with user, it returns the bitmap length it is expecting from user as a negative
           length (and cmd field is 0). When kernel and user agree, kernel returns valid info in
           all fields (ie. link mode length > 0 and cmd is ETHTOOL_GLINKSETTINGS). Based on
           https://github.com/torvalds/linux/commit/3f1ac7a700d039c61d8d8b99f28d605d489a60cf
        */

        ifr->ifr_data = (void *) &ecmd;

        r = ioctl(fd, SIOCETHTOOL, ifr);
        if (r < 0)
                return -errno;

        if (ecmd.req.link_mode_masks_nwords >= 0 || ecmd.req.cmd != ETHTOOL_GLINKSETTINGS)
                return -EOPNOTSUPP;

        ecmd.req.link_mode_masks_nwords = -ecmd.req.link_mode_masks_nwords;

        ifr->ifr_data = (void *) &ecmd;

        r = ioctl(fd, SIOCETHTOOL, ifr);
        if (r < 0)
                return -errno;

        if (ecmd.req.link_mode_masks_nwords <= 0 || ecmd.req.cmd != ETHTOOL_GLINKSETTINGS)
                return -EOPNOTSUPP;

        u = new(struct ethtool_link_usettings, 1);
        if (!u)
                return -ENOMEM;

        *u = (struct ethtool_link_usettings) {
                .base = ecmd.req,
        };

        offset = 0;
        memcpy(u->link_modes.supported, &ecmd.link_mode_data[offset], 4 * ecmd.req.link_mode_masks_nwords);

        offset += ecmd.req.link_mode_masks_nwords;
        memcpy(u->link_modes.advertising, &ecmd.link_mode_data[offset], 4 * ecmd.req.link_mode_masks_nwords);

        offset += ecmd.req.link_mode_masks_nwords;
        memcpy(u->link_modes.lp_advertising, &ecmd.link_mode_data[offset], 4 * ecmd.req.link_mode_masks_nwords);

        *g = u;

        return 0;
}

static int get_gset(int fd, struct ifreq *ifr, struct ethtool_link_usettings **u) {
        struct ethtool_link_usettings *e;
        struct ethtool_cmd ecmd = {
                .cmd = ETHTOOL_GSET,
        };
        int r;

        ifr->ifr_data = (void *) &ecmd;

        r = ioctl(fd, SIOCETHTOOL, ifr);
        if (r < 0)
                return -errno;

        e = new(struct ethtool_link_usettings, 1);
        if (!e)
                return -ENOMEM;

        *e = (struct ethtool_link_usettings) {
                .base.cmd = ETHTOOL_GSET,
                .base.link_mode_masks_nwords = 1,
                .base.speed = ethtool_cmd_speed(&ecmd),
                .base.duplex = ecmd.duplex,
                .base.port = ecmd.port,
                .base.phy_address = ecmd.phy_address,
                .base.autoneg = ecmd.autoneg,
                .base.mdio_support = ecmd.mdio_support,

                .link_modes.supported[0] = ecmd.supported,
                .link_modes.advertising[0] = ecmd.advertising,
                .link_modes.lp_advertising[0] = ecmd.lp_advertising,
        };

        *u = e;

        return 0;
}

static int set_slinksettings(int fd, struct ifreq *ifr, const struct ethtool_link_usettings *u) {
        struct {
                struct ethtool_link_settings req;
                __u32 link_mode_data[3 * ETHTOOL_LINK_MODE_MASK_MAX_KERNEL_NU32];
        } ecmd = {};
        unsigned offset;
        int r;

        if (u->base.cmd != ETHTOOL_GLINKSETTINGS || u->base.link_mode_masks_nwords <= 0)
                return -EINVAL;

        ecmd.req = u->base;
        ecmd.req.cmd = ETHTOOL_SLINKSETTINGS;
        offset = 0;
        memcpy(&ecmd.link_mode_data[offset], u->link_modes.supported, 4 * ecmd.req.link_mode_masks_nwords);

        offset += ecmd.req.link_mode_masks_nwords;
        memcpy(&ecmd.link_mode_data[offset], u->link_modes.advertising, 4 * ecmd.req.link_mode_masks_nwords);

        offset += ecmd.req.link_mode_masks_nwords;
        memcpy(&ecmd.link_mode_data[offset], u->link_modes.lp_advertising, 4 * ecmd.req.link_mode_masks_nwords);

        ifr->ifr_data = (void *) &ecmd;

        r = ioctl(fd, SIOCETHTOOL, ifr);
        if (r < 0)
                return -errno;

        return 0;
}

static int set_sset(int fd, struct ifreq *ifr, const struct ethtool_link_usettings *u) {
        struct ethtool_cmd ecmd = {
                .cmd = ETHTOOL_SSET,
        };
        int r;

        if (u->base.cmd != ETHTOOL_GSET || u->base.link_mode_masks_nwords <= 0)
                return -EINVAL;

        ecmd.supported = u->link_modes.supported[0];
        ecmd.advertising = u->link_modes.advertising[0];
        ecmd.lp_advertising = u->link_modes.lp_advertising[0];

        ethtool_cmd_speed_set(&ecmd, u->base.speed);

        ecmd.duplex = u->base.duplex;
        ecmd.port = u->base.port;
        ecmd.phy_address = u->base.phy_address;
        ecmd.autoneg = u->base.autoneg;
        ecmd.mdio_support = u->base.mdio_support;
        ecmd.eth_tp_mdix = u->base.eth_tp_mdix;
        ecmd.eth_tp_mdix_ctrl = u->base.eth_tp_mdix_ctrl;

        ifr->ifr_data = (void *) &ecmd;

        r = ioctl(fd, SIOCETHTOOL, ifr);
        if (r < 0)
                return -errno;

        return 0;
}

/* If autonegotiation is disabled, the speed and duplex represent the fixed link
 * mode and are writable if the driver supports multiple link modes. If it is
 * enabled then they are read-only. If the link is up they represent the negotiated
 * link mode; if the link is down, the speed is 0, %SPEED_UNKNOWN or the highest
 * enabled speed and @duplex is %DUPLEX_UNKNOWN or the best enabled duplex mode.
 */
int ethtool_set_glinksettings(
                int *fd,
                const char *ifname,
                int autonegotiation,
                uint32_t advertise[static N_ADVERTISE],
                uint64_t speed,
                Duplex duplex,
                NetDevPort port) {
        _cleanup_free_ struct ethtool_link_usettings *u = NULL;
        struct ifreq ifr = {};
        int r;

        assert(advertise);

        if (autonegotiation != AUTONEG_DISABLE && memeqzero(advertise, sizeof(uint32_t) * N_ADVERTISE)) {
                log_info("ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.");
                return 0;
        }

        if (*fd < 0) {
                r = ethtool_connect_or_warn(fd, true);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = get_glinksettings(*fd, &ifr, &u);
        if (r < 0) {
                r = get_gset(*fd, &ifr, &u);
                if (r < 0)
                        return log_warning_errno(r, "ethtool: Cannot get device settings for %s : %m", ifname);
        }

        if (speed > 0)
                u->base.speed = DIV_ROUND_UP(speed, 1000000);

        if (duplex != _DUP_INVALID)
                u->base.duplex = duplex;

        if (port != _NET_DEV_PORT_INVALID)
                u->base.port = port;

        if (autonegotiation >= 0)
                u->base.autoneg = autonegotiation;

        if (!memeqzero(advertise, sizeof(uint32_t) * N_ADVERTISE)) {
                u->base.autoneg = AUTONEG_ENABLE;
                memcpy(&u->link_modes.advertising, advertise, sizeof(uint32_t) * N_ADVERTISE);
                memzero((uint8_t*) &u->link_modes.advertising + sizeof(uint32_t) * N_ADVERTISE,
                        ETHTOOL_LINK_MODE_MASK_MAX_KERNEL_NBYTES - sizeof(uint32_t) * N_ADVERTISE);
        }

        if (u->base.cmd == ETHTOOL_GLINKSETTINGS)
                r = set_slinksettings(*fd, &ifr, u);
        else
                r = set_sset(*fd, &ifr, u);
        if (r < 0)
                return log_warning_errno(r, "ethtool: Cannot set device settings for %s: %m", ifname);

        return r;
}

int ethtool_set_channels(int *fd, const char *ifname, netdev_channels *channels) {
        struct ethtool_channels ecmd = {
                .cmd = ETHTOOL_GCHANNELS
        };
        struct ifreq ifr = {
                .ifr_data = (void*) &ecmd
        };

        bool need_update = false;
        int r;

        if (*fd < 0) {
                r = ethtool_connect_or_warn(fd, true);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = ioctl(*fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return -errno;

        if (channels->rx_count_set && ecmd.rx_count != channels->rx_count) {
                ecmd.rx_count = channels->rx_count;
                need_update = true;
        }

        if (channels->tx_count_set && ecmd.tx_count != channels->tx_count) {
                ecmd.tx_count = channels->tx_count;
                need_update = true;
        }

        if (channels->other_count_set && ecmd.other_count != channels->other_count) {
                ecmd.other_count = channels->other_count;
                need_update = true;
        }

        if (channels->combined_count_set && ecmd.combined_count != channels->combined_count) {
                ecmd.combined_count = channels->combined_count;
                need_update = true;
        }

        if (need_update) {
                ecmd.cmd = ETHTOOL_SCHANNELS;

                r = ioctl(*fd, SIOCETHTOOL, &ifr);
                if (r < 0)
                        return -errno;
        }

        return 0;
}

int ethtool_set_flow_control(int *fd, const char *ifname, int rx, int tx, int autoneg) {
        struct ethtool_pauseparam ecmd = {
                .cmd = ETHTOOL_GPAUSEPARAM
        };
        struct ifreq ifr = {
                .ifr_data = (void*) &ecmd
        };

        bool need_update = false;
        int r;

        if (*fd < 0) {
                r = ethtool_connect_or_warn(fd, true);
                if (r < 0)
                        return r;
        }

        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);

        r = ioctl(*fd, SIOCETHTOOL, &ifr);
        if (r < 0)
                return -errno;

        if (rx >= 0 && ecmd.rx_pause != (uint32_t) rx) {
                ecmd.rx_pause = rx;
                need_update = true;
        }

        if (tx >= 0 && ecmd.tx_pause != (uint32_t) tx) {
                ecmd.tx_pause = tx;
                need_update = true;
        }

        if (autoneg >= 0 && ecmd.autoneg != (uint32_t) autoneg) {
                ecmd.autoneg = autoneg;
                need_update = true;
        }

        if (need_update) {
                ecmd.cmd = ETHTOOL_SPAUSEPARAM;

                r = ioctl(*fd, SIOCETHTOOL, &ifr);
                if (r < 0)
                        return -errno;
        }

        return 0;
}

int config_parse_channel(const char *unit,
                         const char *filename,
                         unsigned line,
                         const char *section,
                         unsigned section_line,
                         const char *lvalue,
                         int ltype,
                         const char *rvalue,
                         void *data,
                         void *userdata) {
        netdev_channels *channels = data;
        uint32_t k;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = safe_atou32(rvalue, &k);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse channel value, ignoring: %s", rvalue);
                return 0;
        }

        if (k < 1) {
                log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid %s value, ignoring: %s", lvalue, rvalue);
                return 0;
        }

        if (streq(lvalue, "RxChannels")) {
                channels->rx_count = k;
                channels->rx_count_set = true;
        } else if (streq(lvalue, "TxChannels")) {
                channels->tx_count = k;
                channels->tx_count_set = true;
        } else if (streq(lvalue, "OtherChannels")) {
                channels->other_count = k;
                channels->other_count_set = true;
        } else if (streq(lvalue, "CombinedChannels")) {
                channels->combined_count = k;
                channels->combined_count_set = true;
        }

        return 0;
}

int config_parse_advertise(const char *unit,
                           const char *filename,
                           unsigned line,
                           const char *section,
                           unsigned section_line,
                           const char *lvalue,
                           int ltype,
                           const char *rvalue,
                           void *data,
                           void *userdata) {
        uint32_t *advertise = data;
        const char *p;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        if (isempty(rvalue)) {
                /* Empty string resets the value. */
                memzero(advertise, sizeof(uint32_t) * N_ADVERTISE);
                return 0;
        }

        for (p = rvalue;;) {
                _cleanup_free_ char *w = NULL;
                enum ethtool_link_mode_bit_indices mode;

                r = extract_first_word(&p, &w, NULL, 0);
                if (r == -ENOMEM)
                        return log_oom();
                if (r < 0) {
                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to split advertise modes '%s', ignoring: %m", rvalue);
                        break;
                }
                if (r == 0)
                        break;

                mode = ethtool_link_mode_bit_from_string(w);
                /* We reuse the kernel provided enum which does not contain negative value. So, the cast
                 * below is mandatory. Otherwise, the check below always passes and access an invalid address. */
                if ((int) mode < 0) {
                        log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse advertise mode, ignoring: %s", w);
                        continue;
                }

                advertise[mode / 32] |= 1UL << (mode % 32);
        }

        return 0;
}

int config_parse_nic_buffer_size(const char *unit,
                                 const char *filename,
                                 unsigned line,
                                 const char *section,
                                 unsigned section_line,
                                 const char *lvalue,
                                 int ltype,
                                 const char *rvalue,
                                 void *data,
                                 void *userdata) {
        netdev_ring_param *ring = data;
        uint32_t k;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = safe_atou32(rvalue, &k);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse interface buffer value, ignoring: %s", rvalue);
                return 0;
        }

        if (k < 1) {
                log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid %s value, ignoring: %s", lvalue, rvalue);
                return 0;
        }

        if (streq(lvalue, "RxBufferSize")) {
                ring->rx_pending = k;
                ring->rx_pending_set = true;
        } else if (streq(lvalue, "RxMiniBufferSize")) {
                ring->rx_mini_pending = k;
                ring->rx_mini_pending_set = true;
        } else if (streq(lvalue, "RxJumboBufferSize")) {
                ring->rx_jumbo_pending = k;
                ring->rx_jumbo_pending_set = true;
        } else if (streq(lvalue, "TxBufferSize")) {
                ring->tx_pending = k;
                ring->tx_pending_set = true;
        }

        return 0;
}
