Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 787 insertions, 0 deletions

diff --git a/src/udev/net/ethtool-util.c b/src/udev/net/ethtool-util.c
new file mode 100644
index 0000000..0dcec03
--- /dev/null
+++ b/src/udev/net/ethtool-util.c
@@ -0,0 +1,787 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <linux/ethtool.h>
+#include <linux/sockios.h>
+
+#include "conf-parser.h"
+#include "ethtool-util.h"
+#include "link-config.h"
+#include "log.h"
+#include "missing.h"
+#include "socket-util.h"
+#include "string-table.h"
+#include "strxcpyx.h"
+#include "util.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_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",
+};
+/* Make sure the array is large enough to fit all bits */
+assert_cc((ELEMENTSOF(ethtool_link_mode_bit_table)-1) / 32 < ELEMENTSOF(((struct link_config){}).advertise));
+
+DEFINE_STRING_TABLE_LOOKUP(ethtool_link_mode_bit, enum ethtool_link_mode_bit_indices);
+
+int ethtool_connect(int *ret) {
+        int fd;
+
+        assert_return(ret, -EINVAL);
+
+        fd = socket_ioctl_fd();
+        if (fd < 0)
+                return fd;
+
+        *ret = fd;
+
+        return 0;
+}
+
+int ethtool_get_driver(int *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 (*fd < 0) {
+                r = ethtool_connect(fd);
+                if (r < 0)
+                        return log_warning_errno(r, "link_config: could not connect to ethtool: %m");
+        }
+
+        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);
+
+        r = ioctl(*fd, SIOCETHTOOL, &ifr);
+        if (r < 0)
+                return -errno;
+
+        d = strdup(ecmd.driver);
+        if (!d)
+                return -ENOMEM;
+
+        *ret = d;
+        return 0;
+}
+
+int ethtool_set_speed(int *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 (*fd < 0) {
+                r = ethtool_connect(fd);
+                if (r < 0)
+                        return log_warning_errno(r, "link_config: could not connect to ethtool: %m");
+        }
+
+        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);
+
+        r = ioctl(*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(*fd, SIOCETHTOOL, &ifr);
+                if (r < 0)
+                        return -errno;
+        }
+
+        return 0;
+}
+
+int ethtool_set_wol(int *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 (*fd < 0) {
+                r = ethtool_connect(fd);
+                if (r < 0)
+                        return log_warning_errno(r, "link_config: could not connect to ethtool: %m");
+        }
+
+        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);
+
+        r = ioctl(*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(*fd, SIOCETHTOOL, &ifr);
+                if (r < 0)
+                        return -errno;
+        }
+
+        return 0;
+}
+
+static int get_stringset(int 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(fd, SIOCETHTOOL, ifr);
+        if (r < 0)
+                return -errno;
+
+        if (!buffer.info.sset_mask)
+                return -EINVAL;
+
+        len = buffer.info.data[0];
+
+        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(fd, SIOCETHTOOL, ifr);
+        if (r < 0)
+                return -errno;
+
+        *gstrings = TAKE_PTR(strings);
+
+        return 0;
+}
+
+static int find_feature_index(struct ethtool_gstrings *strings, const char *feature) {
+        unsigned i;
+
+        for (i = 0; i < strings->len; i++) {
+                if (streq((char *) &strings->data[i * ETH_GSTRING_LEN], feature))
+                        return i;
+        }
+
+        return -1;
+}
+
+int ethtool_set_features(int *fd, const char *ifname, int *features) {
+        _cleanup_free_ struct ethtool_gstrings *strings = NULL;
+        struct ethtool_sfeatures *sfeatures;
+        int block, bit, i, r;
+        struct ifreq ifr = {};
+
+        if (*fd < 0) {
+                r = ethtool_connect(fd);
+                if (r < 0)
+                        return log_warning_errno(r, "link_config: could not connect to ethtool: %m");
+        }
+
+        strscpy(ifr.ifr_name, IFNAMSIZ, ifname);
+
+        r = get_stringset(*fd, &ifr, ETH_SS_FEATURES, &strings);
+        if (r < 0)
+                return log_warning_errno(r, "link_config: 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 = find_feature_index(strings, netdev_feature_table[i]);
+                        if (r < 0) {
+                                log_warning_errno(r, "link_config: could not find feature: %s", netdev_feature_table[i]);
+                                continue;
+                        }
+
+                        block = r / 32;
+                        bit = r % 32;
+
+                        sfeatures->features[block].valid |= 1 << bit;
+
+                        if (features[i])
+                                sfeatures->features[block].requested |= 1 << bit;
+                        else
+                                sfeatures->features[block].requested &= ~(1 << bit);
+                }
+        }
+
+        ifr.ifr_data = (void *) sfeatures;
+
+        r = ioctl(*fd, SIOCETHTOOL, &ifr);
+        if (r < 0)
+                return log_warning_errno(r, "link_config: 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 = new0(struct ethtool_link_usettings , 1);
+        if (!u)
+                return -ENOMEM;
+
+        u->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 = new0(struct ethtool_link_usettings, 1);
+        if (!e)
+                return -ENOMEM;
+
+        e->base.cmd = ETHTOOL_GSET;
+
+        e->base.link_mode_masks_nwords = 1;
+        e->base.speed = ethtool_cmd_speed(&ecmd);
+        e->base.duplex = ecmd.duplex;
+        e->base.port = ecmd.port;
+        e->base.phy_address = ecmd.phy_address;
+        e->base.autoneg = ecmd.autoneg;
+        e->base.mdio_support = ecmd.mdio_support;
+
+        e->link_modes.supported[0] = ecmd.supported;
+        e->link_modes.advertising[0] = ecmd.advertising;
+        e->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, struct link_config *link) {
+        _cleanup_free_ struct ethtool_link_usettings *u = NULL;
+        struct ifreq ifr = {};
+        int r;
+
+        if (link->autonegotiation != AUTONEG_DISABLE && eqzero(link->advertise)) {
+                log_info("link_config: autonegotiation is unset or enabled, the speed and duplex are not writable.");
+                return 0;
+        }
+
+        if (*fd < 0) {
+                r = ethtool_connect(fd);
+                if (r < 0)
+                        return log_warning_errno(r, "link_config: could not connect to ethtool: %m");
+        }
+
+        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, "link_config: Cannot get device settings for %s : %m", ifname);
+        }
+
+        if (link->speed)
+                u->base.speed = DIV_ROUND_UP(link->speed, 1000000);
+
+        if (link->duplex != _DUP_INVALID)
+                u->base.duplex = link->duplex;
+
+        if (link->port != _NET_DEV_PORT_INVALID)
+                u->base.port = link->port;
+
+        if (link->autonegotiation >= 0)
+                u->base.autoneg = link->autonegotiation;
+
+        if (!eqzero(link->advertise)) {
+                u->base.autoneg = AUTONEG_ENABLE;
+                memcpy(&u->link_modes.advertising, link->advertise, sizeof(link->advertise));
+                memzero((uint8_t*) &u->link_modes.advertising + sizeof(link->advertise),
+                        ETHTOOL_LINK_MODE_MASK_MAX_KERNEL_NBYTES - sizeof(link->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, "link_config: Cannot set device settings for %s : %m", ifname);
+
+        return r;
+}
+
+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) {
+        link_config *config = 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, -EINVAL, "Invalid %s value, ignoring: %s", lvalue, rvalue);
+                return 0;
+        }
+
+        if (streq(lvalue, "RxChannels")) {
+                config->channels.rx_count = k;
+                config->channels.rx_count_set = true;
+        } else if (streq(lvalue, "TxChannels")) {
+                config->channels.tx_count = k;
+                config->channels.tx_count_set = true;
+        } else if (streq(lvalue, "OtherChannels")) {
+                config->channels.other_count = k;
+                config->channels.other_count_set = true;
+        } else if (streq(lvalue, "CombinedChannels")) {
+                config->channels.combined_count = k;
+                config->channels.combined_count_set = true;
+        }
+
+        return 0;
+}
+
+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(fd);
+                if (r < 0)
+                        return log_warning_errno(r, "link_config: could not connect to ethtool: %m");
+        }
+
+        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 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) {
+        link_config *config = data;
+        const char *p;
+        int r;
+
+        assert(filename);
+        assert(section);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        if (isempty(rvalue)) {
+                /* Empty string resets the value. */
+                zero(config->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);
+                if (mode < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse advertise mode, ignoring: %s", w);
+                        continue;
+                }
+
+                config->advertise[mode / 32] |= 1UL << (mode % 32);
+        }
+
+        return 0;
+}