Adding upstream version 247.3.upstream/247.3upstream

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

5 files changed, 907 insertions, 0 deletions

diff --git a/src/udev/net/fuzz-link-parser.c b/src/udev/net/fuzz-link-parser.c
new file mode 100644
index 0000000..6f3469c
--- /dev/null
+++ b/src/udev/net/fuzz-link-parser.c
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "fd-util.h"
+#include "fs-util.h"
+#include "fuzz.h"
+#include "link-config.h"
+#include "tmpfile-util.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+        _cleanup_(link_config_ctx_freep) link_config_ctx *ctx = NULL;
+        _cleanup_(unlink_tempfilep) char filename[] = "/tmp/fuzz-link-config.XXXXXX";
+        _cleanup_fclose_ FILE *f = NULL;
+
+        if (size > 65535)
+                return 0;
+
+        if (!getenv("SYSTEMD_LOG_LEVEL"))
+                log_set_max_level(LOG_CRIT);
+
+        assert_se(fmkostemp_safe(filename, "r+", &f) == 0);
+        if (size != 0)
+                assert_se(fwrite(data, size, 1, f) == 1);
+
+        fflush(f);
+        assert_se(link_config_ctx_new(&ctx) >= 0);
+        (void) link_load_one(ctx, filename);
+        return 0;
+}
diff --git a/src/udev/net/fuzz-link-parser.options b/src/udev/net/fuzz-link-parser.options
new file mode 100644
index 0000000..0824b19
--- /dev/null
+++ b/src/udev/net/fuzz-link-parser.options
@@ -0,0 +1,2 @@
+[libfuzzer]
+max_len = 65535
diff --git a/src/udev/net/link-config-gperf.gperf b/src/udev/net/link-config-gperf.gperf
new file mode 100644
index 0000000..20f5d7e
--- /dev/null
+++ b/src/udev/net/link-config-gperf.gperf
@@ -0,0 +1,68 @@
+%{
+#if __GNUC__ >= 7
+_Pragma("GCC diagnostic ignored \"-Wimplicit-fallthrough\"")
+#endif
+#include <stddef.h>
+#include "conf-parser.h"
+#include "ethtool-util.h"
+#include "link-config.h"
+#include "network-internal.h"
+#include "socket-util.h"
+%}
+struct ConfigPerfItem;
+%null_strings
+%language=ANSI-C
+%define slot-name section_and_lvalue
+%define hash-function-name link_config_gperf_hash
+%define lookup-function-name link_config_gperf_lookup
+%readonly-tables
+%omit-struct-type
+%struct-type
+%includes
+%%
+Match.MACAddress,                config_parse_hwaddrs,                  0,                             offsetof(link_config, match_mac)
+Match.PermanentMACAddress,       config_parse_hwaddrs,                  0,                             offsetof(link_config, match_permanent_mac)
+Match.OriginalName,              config_parse_match_ifnames,            0,                             offsetof(link_config, match_name)
+Match.Path,                      config_parse_match_strv,               0,                             offsetof(link_config, match_path)
+Match.Driver,                    config_parse_match_strv,               0,                             offsetof(link_config, match_driver)
+Match.Type,                      config_parse_match_strv,               0,                             offsetof(link_config, match_type)
+Match.Property,                  config_parse_match_property,           0,                             offsetof(link_config, match_property)
+Match.Host,                      config_parse_net_condition,            CONDITION_HOST,                offsetof(link_config, conditions)
+Match.Virtualization,            config_parse_net_condition,            CONDITION_VIRTUALIZATION,      offsetof(link_config, conditions)
+Match.KernelCommandLine,         config_parse_net_condition,            CONDITION_KERNEL_COMMAND_LINE, offsetof(link_config, conditions)
+Match.KernelVersion,             config_parse_net_condition,            CONDITION_KERNEL_VERSION,      offsetof(link_config, conditions)
+Match.Architecture,              config_parse_net_condition,            CONDITION_ARCHITECTURE,        offsetof(link_config, conditions)
+Link.Description,                config_parse_string,                   0,                             offsetof(link_config, description)
+Link.MACAddressPolicy,           config_parse_mac_address_policy,       0,                             offsetof(link_config, mac_address_policy)
+Link.MACAddress,                 config_parse_hwaddr,                   0,                             offsetof(link_config, mac)
+Link.NamePolicy,                 config_parse_name_policy,              0,                             offsetof(link_config, name_policy)
+Link.Name,                       config_parse_ifname,                   0,                             offsetof(link_config, name)
+Link.AlternativeName,            config_parse_ifnames,                  IFNAME_VALID_ALTERNATIVE,      offsetof(link_config, alternative_names)
+Link.AlternativeNamesPolicy,     config_parse_alternative_names_policy, 0,                             offsetof(link_config, alternative_names_policy)
+Link.Alias,                      config_parse_ifalias,                  0,                             offsetof(link_config, alias)
+Link.MTUBytes,                   config_parse_mtu,                      AF_UNSPEC,                     offsetof(link_config, mtu)
+Link.BitsPerSecond,              config_parse_si_uint64,                0,                             offsetof(link_config, speed)
+Link.Duplex,                     config_parse_duplex,                   0,                             offsetof(link_config, duplex)
+Link.AutoNegotiation,            config_parse_tristate,                 0,                             offsetof(link_config, autonegotiation)
+Link.WakeOnLan,                  config_parse_wol,                      0,                             offsetof(link_config, wol)
+Link.Port,                       config_parse_port,                     0,                             offsetof(link_config, port)
+Link.ReceiveChecksumOffload,     config_parse_tristate,                 0,                             offsetof(link_config, features[NET_DEV_FEAT_RX])
+Link.TransmitChecksumOffload,    config_parse_tristate,                 0,                             offsetof(link_config, features[NET_DEV_FEAT_TX])
+Link.GenericSegmentationOffload, config_parse_tristate,                 0,                             offsetof(link_config, features[NET_DEV_FEAT_GSO])
+Link.TCPSegmentationOffload,     config_parse_tristate,                 0,                             offsetof(link_config, features[NET_DEV_FEAT_TSO])
+Link.TCP6SegmentationOffload,    config_parse_tristate,                 0,                             offsetof(link_config, features[NET_DEV_FEAT_TSO6])
+Link.UDPSegmentationOffload,     config_parse_warn_compat,              DISABLED_LEGACY,               0
+Link.GenericReceiveOffload,      config_parse_tristate,                 0,                             offsetof(link_config, features[NET_DEV_FEAT_GRO])
+Link.LargeReceiveOffload,        config_parse_tristate,                 0,                             offsetof(link_config, features[NET_DEV_FEAT_LRO])
+Link.RxChannels,                 config_parse_channel,                  0,                             offsetof(link_config, channels)
+Link.TxChannels,                 config_parse_channel,                  0,                             offsetof(link_config, channels)
+Link.OtherChannels,              config_parse_channel,                  0,                             offsetof(link_config, channels)
+Link.CombinedChannels,           config_parse_channel,                  0,                             offsetof(link_config, channels)
+Link.Advertise,                  config_parse_advertise,                0,                             offsetof(link_config, advertise)
+Link.RxBufferSize,               config_parse_nic_buffer_size,          0,                             offsetof(link_config, ring)
+Link.RxMiniBufferSize,           config_parse_nic_buffer_size,          0,                             offsetof(link_config, ring)
+Link.RxJumboBufferSize,          config_parse_nic_buffer_size,          0,                             offsetof(link_config, ring)
+Link.TxBufferSize,               config_parse_nic_buffer_size,          0,                             offsetof(link_config, ring)
+Link.RxFlowControl,              config_parse_tristate,                 0,                             offsetof(link_config, rx_flow_control)
+Link.TxFlowControl,              config_parse_tristate,                 0,                             offsetof(link_config, tx_flow_control)
+Link.AutoNegotiationFlowControl, config_parse_tristate,                 0,                             offsetof(link_config, autoneg_flow_control)
diff --git a/src/udev/net/link-config.c b/src/udev/net/link-config.c
new file mode 100644
index 0000000..d12fd0e
--- /dev/null
+++ b/src/udev/net/link-config.c
@@ -0,0 +1,711 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <linux/netdevice.h>
+#include <netinet/ether.h>
+#include <unistd.h>
+
+#include "sd-device.h"
+#include "sd-netlink.h"
+
+#include "alloc-util.h"
+#include "conf-files.h"
+#include "conf-parser.h"
+#include "def.h"
+#include "device-private.h"
+#include "device-util.h"
+#include "ethtool-util.h"
+#include "fd-util.h"
+#include "link-config.h"
+#include "log.h"
+#include "memory-util.h"
+#include "netif-naming-scheme.h"
+#include "netlink-util.h"
+#include "network-internal.h"
+#include "parse-util.h"
+#include "path-lookup.h"
+#include "path-util.h"
+#include "proc-cmdline.h"
+#include "random-util.h"
+#include "stat-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+
+struct link_config_ctx {
+        LIST_HEAD(link_config, links);
+
+        int ethtool_fd;
+
+        bool enable_name_policy;
+
+        sd_netlink *rtnl;
+
+        usec_t network_dirs_ts_usec;
+};
+
+static void link_config_free(link_config *link) {
+        if (!link)
+                return;
+
+        free(link->filename);
+
+        set_free_free(link->match_mac);
+        set_free_free(link->match_permanent_mac);
+        strv_free(link->match_path);
+        strv_free(link->match_driver);
+        strv_free(link->match_type);
+        strv_free(link->match_name);
+        strv_free(link->match_property);
+        condition_free_list(link->conditions);
+
+        free(link->description);
+        free(link->mac);
+        free(link->name_policy);
+        free(link->name);
+        strv_free(link->alternative_names);
+        free(link->alternative_names_policy);
+        free(link->alias);
+
+        free(link);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(link_config*, link_config_free);
+
+static void link_configs_free(link_config_ctx *ctx) {
+        link_config *link, *link_next;
+
+        if (!ctx)
+                return;
+
+        LIST_FOREACH_SAFE(links, link, link_next, ctx->links)
+                link_config_free(link);
+}
+
+void link_config_ctx_free(link_config_ctx *ctx) {
+        if (!ctx)
+                return;
+
+        safe_close(ctx->ethtool_fd);
+
+        sd_netlink_unref(ctx->rtnl);
+
+        link_configs_free(ctx);
+
+        free(ctx);
+
+        return;
+}
+
+int link_config_ctx_new(link_config_ctx **ret) {
+        _cleanup_(link_config_ctx_freep) link_config_ctx *ctx = NULL;
+
+        if (!ret)
+                return -EINVAL;
+
+        ctx = new0(link_config_ctx, 1);
+        if (!ctx)
+                return -ENOMEM;
+
+        LIST_HEAD_INIT(ctx->links);
+
+        ctx->ethtool_fd = -1;
+
+        ctx->enable_name_policy = true;
+
+        *ret = TAKE_PTR(ctx);
+
+        return 0;
+}
+
+int link_load_one(link_config_ctx *ctx, const char *filename) {
+        _cleanup_(link_config_freep) link_config *link = NULL;
+        _cleanup_fclose_ FILE *file = NULL;
+        _cleanup_free_ char *name = NULL;
+        size_t i;
+        int r;
+
+        assert(ctx);
+        assert(filename);
+
+        file = fopen(filename, "re");
+        if (!file)
+                return errno == ENOENT ? 0 : -errno;
+
+        if (null_or_empty_fd(fileno(file))) {
+                log_debug("Skipping empty file: %s", filename);
+                return 0;
+        }
+
+        name = strdup(filename);
+        if (!name)
+                return -ENOMEM;
+
+        link = new(link_config, 1);
+        if (!link)
+                return -ENOMEM;
+
+        *link = (link_config) {
+                .filename = TAKE_PTR(name),
+                .mac_address_policy = _MAC_ADDRESS_POLICY_INVALID,
+                .wol = _WOL_INVALID,
+                .duplex = _DUP_INVALID,
+                .port = _NET_DEV_PORT_INVALID,
+                .autonegotiation = -1,
+                .rx_flow_control = -1,
+                .tx_flow_control = -1,
+                .autoneg_flow_control = -1,
+        };
+
+        for (i = 0; i < ELEMENTSOF(link->features); i++)
+                link->features[i] = -1;
+
+        r = config_parse(NULL, filename, file,
+                         "Match\0Link\0",
+                         config_item_perf_lookup, link_config_gperf_lookup,
+                         CONFIG_PARSE_WARN, link,
+                         NULL);
+        if (r < 0)
+                return r;
+
+        if (set_isempty(link->match_mac) && set_isempty(link->match_permanent_mac) &&
+            strv_isempty(link->match_path) && strv_isempty(link->match_driver) && strv_isempty(link->match_type) &&
+            strv_isempty(link->match_name) && strv_isempty(link->match_property) && !link->conditions) {
+                log_warning("%s: No valid settings found in the [Match] section, ignoring file. "
+                            "To match all interfaces, add OriginalName=* in the [Match] section.",
+                            filename);
+                return 0;
+        }
+
+        if (!condition_test_list(link->conditions, environ, NULL, NULL, NULL)) {
+                log_debug("%s: Conditions do not match the system environment, skipping.", filename);
+                return 0;
+        }
+
+        if (IN_SET(link->mac_address_policy, MAC_ADDRESS_POLICY_PERSISTENT, MAC_ADDRESS_POLICY_RANDOM) && link->mac) {
+                log_warning("%s: MACAddress= in [Link] section will be ignored when MACAddressPolicy= "
+                            "is set to \"persistent\" or \"random\".",
+                            filename);
+                link->mac = mfree(link->mac);
+        }
+
+        log_debug("Parsed configuration file %s", filename);
+
+        LIST_PREPEND(links, ctx->links, TAKE_PTR(link));
+        return 0;
+}
+
+static bool enable_name_policy(void) {
+        bool b;
+
+        return proc_cmdline_get_bool("net.ifnames", &b) <= 0 || b;
+}
+
+static int link_unsigned_attribute(sd_device *device, const char *attr, unsigned *type) {
+        const char *s;
+        int r;
+
+        r = sd_device_get_sysattr_value(device, attr, &s);
+        if (r < 0)
+                return log_device_debug_errno(device, r, "Failed to query %s: %m", attr);
+
+        r = safe_atou(s, type);
+        if (r < 0)
+                return log_device_warning_errno(device, r, "Failed to parse %s \"%s\": %m", attr, s);
+
+        log_device_debug(device, "Device has %s=%u", attr, *type);
+        return 0;
+}
+
+int link_config_load(link_config_ctx *ctx) {
+        _cleanup_strv_free_ char **files = NULL;
+        char **f;
+        int r;
+
+        link_configs_free(ctx);
+
+        if (!enable_name_policy()) {
+                ctx->enable_name_policy = false;
+                log_info("Network interface NamePolicy= disabled on kernel command line, ignoring.");
+        }
+
+        /* update timestamp */
+        paths_check_timestamp(NETWORK_DIRS, &ctx->network_dirs_ts_usec, true);
+
+        r = conf_files_list_strv(&files, ".link", NULL, 0, NETWORK_DIRS);
+        if (r < 0)
+                return log_error_errno(r, "failed to enumerate link files: %m");
+
+        STRV_FOREACH_BACKWARDS(f, files) {
+                r = link_load_one(ctx, *f);
+                if (r < 0)
+                        log_error_errno(r, "Failed to load %s, ignoring: %m", *f);
+        }
+
+        return 0;
+}
+
+bool link_config_should_reload(link_config_ctx *ctx) {
+        return paths_check_timestamp(NETWORK_DIRS, &ctx->network_dirs_ts_usec, false);
+}
+
+int link_config_get(link_config_ctx *ctx, sd_device *device, link_config **ret) {
+        unsigned name_assign_type = NET_NAME_UNKNOWN;
+        struct ether_addr permanent_mac = {};
+        unsigned short iftype = 0;
+        link_config *link;
+        const char *name;
+        int ifindex, r;
+
+        assert(ctx);
+        assert(device);
+        assert(ret);
+
+        r = sd_device_get_sysname(device, &name);
+        if (r < 0)
+                return r;
+
+        r = sd_device_get_ifindex(device, &ifindex);
+        if (r < 0)
+                return r;
+
+        r = rtnl_get_link_iftype(&ctx->rtnl, ifindex, &iftype);
+        if (r < 0)
+                return r;
+
+        r = ethtool_get_permanent_macaddr(&ctx->ethtool_fd, name, &permanent_mac);
+        if (r < 0)
+                log_device_debug_errno(device, r, "Failed to get permanent MAC address, ignoring: %m");
+
+        (void) link_unsigned_attribute(device, "name_assign_type", &name_assign_type);
+
+        LIST_FOREACH(links, link, ctx->links) {
+                if (net_match_config(link->match_mac, link->match_permanent_mac, link->match_path, link->match_driver,
+                                     link->match_type, link->match_name, link->match_property, NULL, NULL, NULL,
+                                     device, NULL, &permanent_mac, NULL, iftype, NULL, NULL, 0, NULL, NULL)) {
+
+                        if (link->match_name && !strv_contains(link->match_name, "*") && name_assign_type == NET_NAME_ENUM)
+                                log_device_warning(device, "Config file %s is applied to device based on potentially unpredictable interface name.",
+                                                   link->filename);
+                        else
+                                log_device_debug(device, "Config file %s is applied", link->filename);
+
+                        *ret = link;
+                        return 0;
+                }
+        }
+
+        return -ENOENT;
+}
+
+static int link_config_apply_ethtool_settings(int *ethtool_fd, const link_config *config, sd_device *device) {
+        const char *name;
+        int r;
+
+        assert(ethtool_fd);
+        assert(config);
+        assert(device);
+
+        r = sd_device_get_sysname(device, &name);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Failed to get sysname: %m");
+
+        r = ethtool_set_glinksettings(ethtool_fd, name,
+                                      config->autonegotiation, config->advertise,
+                                      config->speed, config->duplex, config->port);
+        if (r < 0) {
+                if (config->port != _NET_DEV_PORT_INVALID)
+                        log_device_warning_errno(device, r, "Could not set port '%s', ignoring: %m", port_to_string(config->port));
+
+                if (!eqzero(config->advertise))
+                        log_device_warning_errno(device, r, "Could not set advertise mode, ignoring: %m"); /* TODO: include modes in the log message. */
+
+                if (config->speed) {
+                        unsigned speed = DIV_ROUND_UP(config->speed, 1000000);
+                        if (r == -EOPNOTSUPP) {
+                                r = ethtool_set_speed(ethtool_fd, name, speed, config->duplex);
+                                if (r < 0)
+                                        log_device_warning_errno(device, r, "Could not set speed to %uMbps, ignoring: %m", speed);
+                        }
+                }
+
+                if (config->duplex != _DUP_INVALID)
+                        log_device_warning_errno(device, r, "Could not set duplex to %s, ignoring: %m", duplex_to_string(config->duplex));
+        }
+
+        r = ethtool_set_wol(ethtool_fd, name, config->wol);
+        if (r < 0)
+                log_device_warning_errno(device, r, "Could not set WakeOnLan to %s, ignoring: %m", wol_to_string(config->wol));
+
+        r = ethtool_set_features(ethtool_fd, name, config->features);
+        if (r < 0)
+                log_device_warning_errno(device, r, "Could not set offload features, ignoring: %m");
+
+        if (config->channels.rx_count_set || config->channels.tx_count_set || config->channels.other_count_set || config->channels.combined_count_set) {
+                r = ethtool_set_channels(ethtool_fd, name, &config->channels);
+                if (r < 0)
+                        log_device_warning_errno(device, r, "Could not set channels, ignoring: %m");
+        }
+
+        if (config->ring.rx_pending_set || config->ring.rx_mini_pending_set || config->ring.rx_jumbo_pending_set || config->ring.tx_pending_set) {
+                r = ethtool_set_nic_buffer_size(ethtool_fd, name, &config->ring);
+                if (r < 0)
+                        log_device_warning_errno(device, r, "Could not set ring buffer, ignoring: %m");
+        }
+
+        if (config->rx_flow_control >= 0 || config->tx_flow_control >= 0 || config->autoneg_flow_control >= 0) {
+                r = ethtool_set_flow_control(ethtool_fd, name, config->rx_flow_control, config->tx_flow_control, config->autoneg_flow_control);
+                if (r < 0)
+                        log_device_warning_errno(device, r, "Could not set flow control, ignoring: %m");
+        }
+
+        return 0;
+}
+
+static int get_mac(sd_device *device, MACAddressPolicy policy, struct ether_addr *mac) {
+        unsigned addr_type;
+        bool want_random = policy == MAC_ADDRESS_POLICY_RANDOM;
+        int r;
+
+        assert(IN_SET(policy, MAC_ADDRESS_POLICY_RANDOM, MAC_ADDRESS_POLICY_PERSISTENT));
+
+        r = link_unsigned_attribute(device, "addr_assign_type", &addr_type);
+        if (r < 0)
+                return r;
+        switch (addr_type) {
+        case NET_ADDR_SET:
+                return log_device_debug(device, "MAC on the device already set by userspace");
+        case NET_ADDR_STOLEN:
+                return log_device_debug(device, "MAC on the device already set based on another device");
+        case NET_ADDR_RANDOM:
+        case NET_ADDR_PERM:
+                break;
+        default:
+                log_device_warning(device, "Unknown addr_assign_type %u, ignoring", addr_type);
+                return 0;
+        }
+
+        if (want_random == (addr_type == NET_ADDR_RANDOM))
+                return log_device_debug(device, "MAC on the device already matches policy *%s*",
+                                        mac_address_policy_to_string(policy));
+
+        if (want_random) {
+                log_device_debug(device, "Using random bytes to generate MAC");
+
+                /* We require genuine randomness here, since we want to make sure we won't collide with other
+                 * systems booting up at the very same time. We do allow RDRAND however, since this is not
+                 * cryptographic key material. */
+                r = genuine_random_bytes(mac->ether_addr_octet, ETH_ALEN, RANDOM_ALLOW_RDRAND);
+                if (r < 0)
+                        return log_device_error_errno(device, r, "Failed to acquire random data to generate MAC: %m");
+        } else {
+                uint64_t result;
+
+                r = net_get_unique_predictable_data(device,
+                                                    naming_scheme_has(NAMING_STABLE_VIRTUAL_MACS),
+                                                    &result);
+                if (r < 0)
+                        return log_device_warning_errno(device, r, "Could not generate persistent MAC: %m");
+
+                log_device_debug(device, "Using generated persistent MAC address");
+                assert_cc(ETH_ALEN <= sizeof(result));
+                memcpy(mac->ether_addr_octet, &result, ETH_ALEN);
+        }
+
+        /* see eth_random_addr in the kernel */
+        mac->ether_addr_octet[0] &= 0xfe;  /* clear multicast bit */
+        mac->ether_addr_octet[0] |= 0x02;  /* set local assignment bit (IEEE802) */
+        return 1;
+}
+
+static int link_config_apply_rtnl_settings(sd_netlink **rtnl, const link_config *config, sd_device *device) {
+        struct ether_addr generated_mac, *mac = NULL;
+        int ifindex, r;
+
+        assert(rtnl);
+        assert(config);
+        assert(device);
+
+        r = sd_device_get_ifindex(device, &ifindex);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Could not find ifindex: %m");
+
+        if (IN_SET(config->mac_address_policy, MAC_ADDRESS_POLICY_PERSISTENT, MAC_ADDRESS_POLICY_RANDOM)) {
+                if (get_mac(device, config->mac_address_policy, &generated_mac) > 0)
+                        mac = &generated_mac;
+        } else
+                mac = config->mac;
+
+        r = rtnl_set_link_properties(rtnl, ifindex, config->alias, mac, config->mtu);
+        if (r < 0)
+                log_device_warning_errno(device, r, "Could not set Alias=, MACAddress= or MTU=, ignoring: %m");
+
+        return 0;
+}
+
+static int link_config_generate_new_name(const link_config_ctx *ctx, const link_config *config, sd_device *device, const char **ret_name) {
+        unsigned name_type = NET_NAME_UNKNOWN;
+        const char *new_name = NULL;
+        NamePolicy policy;
+        int r;
+
+        assert(ctx);
+        assert(config);
+        assert(device);
+        assert(ret_name);
+
+        (void) link_unsigned_attribute(device, "name_assign_type", &name_type);
+
+        if (IN_SET(name_type, NET_NAME_USER, NET_NAME_RENAMED)
+            && !naming_scheme_has(NAMING_ALLOW_RERENAMES)) {
+                log_device_debug(device, "Device already has a name given by userspace, not renaming.");
+                goto no_rename;
+        }
+
+        if (ctx->enable_name_policy && config->name_policy)
+                for (NamePolicy *p = config->name_policy; *p != _NAMEPOLICY_INVALID; p++) {
+                        policy = *p;
+
+                        switch (policy) {
+                        case NAMEPOLICY_KERNEL:
+                                if (name_type != NET_NAME_PREDICTABLE)
+                                        continue;
+
+                                /* The kernel claims to have given a predictable name, keep it. */
+                                log_device_debug(device, "Policy *%s*: keeping predictable kernel name",
+                                                 name_policy_to_string(policy));
+                                goto no_rename;
+                        case NAMEPOLICY_KEEP:
+                                if (!IN_SET(name_type, NET_NAME_USER, NET_NAME_RENAMED))
+                                        continue;
+
+                                log_device_debug(device, "Policy *%s*: keeping existing userspace name",
+                                                 name_policy_to_string(policy));
+                                goto no_rename;
+                        case NAMEPOLICY_DATABASE:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE", &new_name);
+                                break;
+                        case NAMEPOLICY_ONBOARD:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_ONBOARD", &new_name);
+                                break;
+                        case NAMEPOLICY_SLOT:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_SLOT", &new_name);
+                                break;
+                        case NAMEPOLICY_PATH:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_PATH", &new_name);
+                                break;
+                        case NAMEPOLICY_MAC:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_MAC", &new_name);
+                                break;
+                        default:
+                                assert_not_reached("invalid policy");
+                        }
+                        if (ifname_valid(new_name))
+                                break;
+                }
+
+        if (new_name) {
+                log_device_debug(device, "Policy *%s* yields \"%s\".", name_policy_to_string(policy), new_name);
+                *ret_name = new_name;
+                return 0;
+        }
+
+        if (config->name) {
+                log_device_debug(device, "Policies didn't yield a name, using specified Name=%s.", config->name);
+                *ret_name = config->name;
+                return 0;
+        }
+
+        log_device_debug(device, "Policies didn't yield a name and Name= is not given, not renaming.");
+no_rename:
+        r = sd_device_get_sysname(device, ret_name);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Failed to get sysname: %m");
+
+        return 0;
+}
+
+static int link_config_apply_alternative_names(sd_netlink **rtnl, const link_config *config, sd_device *device, const char *new_name) {
+        _cleanup_strv_free_ char **altnames = NULL, **current_altnames = NULL;
+        const char *current_name;
+        int ifindex, r;
+
+        assert(rtnl);
+        assert(config);
+        assert(device);
+
+        r = sd_device_get_sysname(device, &current_name);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Failed to get sysname: %m");
+
+        r = sd_device_get_ifindex(device, &ifindex);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Could not find ifindex: %m");
+
+        if (config->alternative_names) {
+                altnames = strv_copy(config->alternative_names);
+                if (!altnames)
+                        return log_oom();
+        }
+
+        if (config->alternative_names_policy)
+                for (NamePolicy *p = config->alternative_names_policy; *p != _NAMEPOLICY_INVALID; p++) {
+                        const char *n = NULL;
+
+                        switch (*p) {
+                        case NAMEPOLICY_DATABASE:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE", &n);
+                                break;
+                        case NAMEPOLICY_ONBOARD:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_ONBOARD", &n);
+                                break;
+                        case NAMEPOLICY_SLOT:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_SLOT", &n);
+                                break;
+                        case NAMEPOLICY_PATH:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_PATH", &n);
+                                break;
+                        case NAMEPOLICY_MAC:
+                                (void) sd_device_get_property_value(device, "ID_NET_NAME_MAC", &n);
+                                break;
+                        default:
+                                assert_not_reached("invalid policy");
+                        }
+                        if (!isempty(n)) {
+                                r = strv_extend(&altnames, n);
+                                if (r < 0)
+                                        return log_oom();
+                        }
+                }
+
+        if (new_name)
+                strv_remove(altnames, new_name);
+        strv_remove(altnames, current_name);
+
+        r = rtnl_get_link_alternative_names(rtnl, ifindex, &current_altnames);
+        if (r < 0)
+                log_device_debug_errno(device, r, "Failed to get alternative names, ignoring: %m");
+
+        char **p;
+        STRV_FOREACH(p, current_altnames)
+                strv_remove(altnames, *p);
+
+        strv_uniq(altnames);
+        strv_sort(altnames);
+        r = rtnl_set_link_alternative_names(rtnl, ifindex, altnames);
+        if (r < 0)
+                log_device_full_errno(device, r == -EOPNOTSUPP ? LOG_DEBUG : LOG_WARNING, r,
+                                      "Could not set AlternativeName= or apply AlternativeNamesPolicy=, ignoring: %m");
+
+        return 0;
+}
+
+int link_config_apply(link_config_ctx *ctx, const link_config *config, sd_device *device, const char **ret_name) {
+        const char *new_name;
+        DeviceAction a;
+        int r;
+
+        assert(ctx);
+        assert(config);
+        assert(device);
+        assert(ret_name);
+
+        r = device_get_action(device, &a);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Failed to get ACTION= property: %m");
+
+        if (!IN_SET(a, DEVICE_ACTION_ADD, DEVICE_ACTION_BIND, DEVICE_ACTION_MOVE)) {
+                log_device_debug(device, "Skipping to apply .link settings on '%s' uevent.", device_action_to_string(a));
+
+                r = sd_device_get_sysname(device, ret_name);
+                if (r < 0)
+                        return log_device_error_errno(device, r, "Failed to get sysname: %m");
+
+                return 0;
+        }
+
+        r = link_config_apply_ethtool_settings(&ctx->ethtool_fd, config, device);
+        if (r < 0)
+                return r;
+
+        r = link_config_apply_rtnl_settings(&ctx->rtnl, config, device);
+        if (r < 0)
+                return r;
+
+        if (a == DEVICE_ACTION_MOVE) {
+                log_device_debug(device, "Skipping to apply Name= and NamePolicy= on '%s' uevent.", device_action_to_string(a));
+
+                r = sd_device_get_sysname(device, &new_name);
+                if (r < 0)
+                        return log_device_error_errno(device, r, "Failed to get sysname: %m");
+        } else {
+                r = link_config_generate_new_name(ctx, config, device, &new_name);
+                if (r < 0)
+                        return r;
+        }
+
+        r = link_config_apply_alternative_names(&ctx->rtnl, config, device, new_name);
+        if (r < 0)
+                return r;
+
+        *ret_name = new_name;
+        return 0;
+}
+
+int link_get_driver(link_config_ctx *ctx, sd_device *device, char **ret) {
+        const char *name;
+        char *driver = NULL;
+        int r;
+
+        r = sd_device_get_sysname(device, &name);
+        if (r < 0)
+                return r;
+
+        r = ethtool_get_driver(&ctx->ethtool_fd, name, &driver);
+        if (r < 0)
+                return r;
+
+        *ret = driver;
+        return 0;
+}
+
+static const char* const mac_address_policy_table[_MAC_ADDRESS_POLICY_MAX] = {
+        [MAC_ADDRESS_POLICY_PERSISTENT] = "persistent",
+        [MAC_ADDRESS_POLICY_RANDOM] = "random",
+        [MAC_ADDRESS_POLICY_NONE] = "none",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(mac_address_policy, MACAddressPolicy);
+DEFINE_CONFIG_PARSE_ENUM_WITH_DEFAULT(
+        config_parse_mac_address_policy,
+        mac_address_policy,
+        MACAddressPolicy,
+        MAC_ADDRESS_POLICY_NONE,
+        "Failed to parse MAC address policy");
+
+static const char* const name_policy_table[_NAMEPOLICY_MAX] = {
+        [NAMEPOLICY_KERNEL] = "kernel",
+        [NAMEPOLICY_KEEP] = "keep",
+        [NAMEPOLICY_DATABASE] = "database",
+        [NAMEPOLICY_ONBOARD] = "onboard",
+        [NAMEPOLICY_SLOT] = "slot",
+        [NAMEPOLICY_PATH] = "path",
+        [NAMEPOLICY_MAC] = "mac",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
+DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy,
+                          _NAMEPOLICY_INVALID,
+                          "Failed to parse interface name policy");
+
+static const char* const alternative_names_policy_table[_NAMEPOLICY_MAX] = {
+        [NAMEPOLICY_DATABASE] = "database",
+        [NAMEPOLICY_ONBOARD] = "onboard",
+        [NAMEPOLICY_SLOT] = "slot",
+        [NAMEPOLICY_PATH] = "path",
+        [NAMEPOLICY_MAC] = "mac",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(alternative_names_policy, NamePolicy);
+DEFINE_CONFIG_PARSE_ENUMV(config_parse_alternative_names_policy, alternative_names_policy, NamePolicy,
+                          _NAMEPOLICY_INVALID,
+                          "Failed to parse alternative names policy");
diff --git a/src/udev/net/link-config.h b/src/udev/net/link-config.h
new file mode 100644
index 0000000..eab1849
--- /dev/null
+++ b/src/udev/net/link-config.h
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "sd-device.h"
+
+#include "condition.h"
+#include "conf-parser.h"
+#include "ethtool-util.h"
+#include "list.h"
+#include "set.h"
+
+typedef struct link_config_ctx link_config_ctx;
+typedef struct link_config link_config;
+
+typedef enum MACAddressPolicy {
+        MAC_ADDRESS_POLICY_PERSISTENT,
+        MAC_ADDRESS_POLICY_RANDOM,
+        MAC_ADDRESS_POLICY_NONE,
+        _MAC_ADDRESS_POLICY_MAX,
+        _MAC_ADDRESS_POLICY_INVALID = -1
+} MACAddressPolicy;
+
+typedef enum NamePolicy {
+        NAMEPOLICY_KERNEL,
+        NAMEPOLICY_KEEP,
+        NAMEPOLICY_DATABASE,
+        NAMEPOLICY_ONBOARD,
+        NAMEPOLICY_SLOT,
+        NAMEPOLICY_PATH,
+        NAMEPOLICY_MAC,
+        _NAMEPOLICY_MAX,
+        _NAMEPOLICY_INVALID = -1
+} NamePolicy;
+
+struct link_config {
+        char *filename;
+
+        Set *match_mac;
+        Set *match_permanent_mac;
+        char **match_path;
+        char **match_driver;
+        char **match_type;
+        char **match_name;
+        char **match_property;
+        LIST_HEAD(Condition, conditions);
+
+        char *description;
+        struct ether_addr *mac;
+        MACAddressPolicy mac_address_policy;
+        NamePolicy *name_policy;
+        NamePolicy *alternative_names_policy;
+        char *name;
+        char **alternative_names;
+        char *alias;
+        uint32_t mtu;
+        uint64_t speed;
+        Duplex duplex;
+        int autonegotiation;
+        uint32_t advertise[N_ADVERTISE];
+        WakeOnLan wol;
+        NetDevPort port;
+        int features[_NET_DEV_FEAT_MAX];
+        netdev_channels channels;
+        netdev_ring_param ring;
+        int rx_flow_control;
+        int tx_flow_control;
+        int autoneg_flow_control;
+
+        LIST_FIELDS(link_config, links);
+};
+
+int link_config_ctx_new(link_config_ctx **ret);
+void link_config_ctx_free(link_config_ctx *ctx);
+DEFINE_TRIVIAL_CLEANUP_FUNC(link_config_ctx*, link_config_ctx_free);
+
+int link_load_one(link_config_ctx *ctx, const char *filename);
+int link_config_load(link_config_ctx *ctx);
+bool link_config_should_reload(link_config_ctx *ctx);
+
+int link_config_get(link_config_ctx *ctx, sd_device *device, link_config **ret);
+int link_config_apply(link_config_ctx *ctx, const link_config *config, sd_device *device, const char **ret_name);
+int link_get_driver(link_config_ctx *ctx, sd_device *device, char **ret);
+
+const char *name_policy_to_string(NamePolicy p) _const_;
+NamePolicy name_policy_from_string(const char *p) _pure_;
+
+const char *alternative_names_policy_to_string(NamePolicy p) _const_;
+NamePolicy alternative_names_policy_from_string(const char *p) _pure_;
+
+const char *mac_address_policy_to_string(MACAddressPolicy p) _const_;
+MACAddressPolicy mac_address_policy_from_string(const char *p) _pure_;
+
+/* gperf lookup function */
+const struct ConfigPerfItem* link_config_gperf_lookup(const char *key, GPERF_LEN_TYPE length);
+
+CONFIG_PARSER_PROTOTYPE(config_parse_mac_address_policy);
+CONFIG_PARSER_PROTOTYPE(config_parse_name_policy);
+CONFIG_PARSER_PROTOTYPE(config_parse_alternative_names_policy);