#include <netinet/ether.h>

#include <linux/netdevice.h>

#include "sd-netlink.h"

#include "alloc-util.h"

#include "conf-files.h"

#include "conf-parser.h"

#include "ethtool-util.h"

#include "fd-util.h"

#include "libudev-private.h"

#include "link-config.h"

#include "log.h"

#include "missing.h"

#include "netlink-util.h"

#include "network-internal.h"

#include "parse-util.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"

#include "util.h"

struct link_config_ctx {

LIST_HEAD(link_config, links);

int ethtool_fd;

bool enable_name_policy;

sd_netlink *rtnl;

usec_t link_dirs_ts_usec;

};

static const char* const link_dirs[] = {

"/etc/systemd/network",

"/run/systemd/network",

"/usr/lib/systemd/network",

#ifdef HAVE_SPLIT_USR

"/lib/systemd/network",

#endif

NULL};

static void link_config_free(link_config *link) {

if (!link)

return;

free(link->filename);

free(link->match_mac);

strv_free(link->match_path);

strv_free(link->match_driver);

strv_free(link->match_type);

free(link->match_name);

free(link->match_host);

free(link->match_virt);

free(link->match_kernel);

free(link->match_arch);

free(link->description);

free(link->mac);

free(link->name_policy);

free(link->name);

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;

}

DEFINE_TRIVIAL_CLEANUP_FUNC(link_config_ctx*, link_config_ctx_free);

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 = ctx;

ctx = NULL;

return 0;

}

static int load_link(link_config_ctx *ctx, const char *filename) {

_cleanup_(link_config_freep) link_config *link = NULL;

_cleanup_fclose_ FILE *file = NULL;

int r;

assert(ctx);

assert(filename);

file = fopen(filename, "re");

if (!file) {

if (errno == ENOENT)

return 0;

else

return -errno;

}

if (null_or_empty_fd(fileno(file))) {

log_debug("Skipping empty file: %s", filename);

return 0;

}

link = new0(link_config, 1);

if (!link)

return log_oom();

link->mac_policy = _MACPOLICY_INVALID;

link->wol = _WOL_INVALID;

link->duplex = _DUP_INVALID;

r = config_parse(NULL, filename, file,

"Match\0Link\0Ethernet\0",

config_item_perf_lookup, link_config_gperf_lookup,

false, false, true, link);

if (r < 0)

return r;

else

log_debug("Parsed configuration file %s", filename);

if (link->mtu > UINT_MAX || link->speed > UINT_MAX)

return -ERANGE;

link->filename = strdup(filename);

LIST_PREPEND(links, ctx->links, link);

link = NULL;

return 0;

}

static bool enable_name_policy(void) {

_cleanup_free_ char *line = NULL;

const char *word, *state;

int r;

size_t l;

r = proc_cmdline(&line);

if (r < 0) {

log_warning_errno(r, "Failed to read /proc/cmdline, ignoring: %m");

return true;

}

FOREACH_WORD_QUOTED(word, l, line, state)

if (strneq(word, "net.ifnames=0", l))

return false;

return true;

}

int link_config_load(link_config_ctx *ctx) {

int r;

_cleanup_strv_free_ char **files;

char **f;

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(link_dirs, &ctx->link_dirs_ts_usec, true);

r = conf_files_list_strv(&files, ".link", NULL, link_dirs);

if (r < 0)

return log_error_errno(r, "failed to enumerate link files: %m");

STRV_FOREACH_BACKWARDS(f, files) {

r = load_link(ctx, *f);

if (r < 0)

return r;

}

return 0;

}

bool link_config_should_reload(link_config_ctx *ctx) {

return paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, false);

}

int link_config_get(link_config_ctx *ctx, struct udev_device *device,

link_config **ret) {

link_config *link;

assert(ctx);

assert(device);

assert(ret);

LIST_FOREACH(links, link, ctx->links) {

const char* attr_value;

attr_value = udev_device_get_sysattr_value(device, "address");

if (net_match_config(link->match_mac, link->match_path, link->match_driver,

link->match_type, link->match_name, link->match_host,

link->match_virt, link->match_kernel, link->match_arch,

attr_value ? ether_aton(attr_value) : NULL,

udev_device_get_property_value(device, "ID_PATH"),

udev_device_get_driver(udev_device_get_parent(device)),

udev_device_get_property_value(device, "ID_NET_DRIVER"),

udev_device_get_devtype(device),

udev_device_get_sysname(device))) {

if (link->match_name) {

unsigned char name_assign_type = NET_NAME_UNKNOWN;

attr_value = udev_device_get_sysattr_value(device, "name_assign_type");

if (attr_value)

(void) safe_atou8(attr_value, &name_assign_type);

if (name_assign_type == NET_NAME_ENUM) {

log_warning("Config file %s applies to device based on potentially unpredictable interface name '%s'",

link->filename, udev_device_get_sysname(device));

*ret = link;

return 0;

} else if (name_assign_type == NET_NAME_RENAMED) {

log_warning("Config file %s matches device based on renamed interface name '%s', ignoring",

link->filename, udev_device_get_sysname(device));

continue;

}

}

log_debug("Config file %s applies to device %s",

link->filename, udev_device_get_sysname(device));

*ret = link;

return 0;

}

}

*ret = NULL;

return -ENOENT;

}

static bool mac_is_random(struct udev_device *device) {

const char *s;

unsigned type;

int r;

/* if we can't get the assign type, assume it is not random */

s = udev_device_get_sysattr_value(device, "addr_assign_type");

if (!s)

return false;

r = safe_atou(s, &type);

if (r < 0)

return false;

return type == NET_ADDR_RANDOM;

}

static bool should_rename(struct udev_device *device, bool respect_predictable) {

const char *s;

unsigned type;

int r;

/* if we can't get the assgin type, assume we should rename */

s = udev_device_get_sysattr_value(device, "name_assign_type");

if (!s)

return true;

r = safe_atou(s, &type);

if (r < 0)

return true;

switch (type) {

case NET_NAME_USER:

case NET_NAME_RENAMED:

/* these were already named by userspace, do not touch again */

return false;

case NET_NAME_PREDICTABLE:

/* the kernel claims to have given a predictable name */

if (respect_predictable)

return false;

/* fall through */

case NET_NAME_ENUM:

default:

/* the name is known to be bad, or of an unknown type */

return true;

}

}

static int get_mac(struct udev_device *device, bool want_random,

struct ether_addr *mac) {

int r;

if (want_random)

random_bytes(mac->ether_addr_octet, ETH_ALEN);

else {

uint64_t result;

r = net_get_unique_predictable_data(device, &result);

if (r < 0)

return r;

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 0;

}

int link_config_apply(link_config_ctx *ctx, link_config *config,

struct udev_device *device, const char **name) {

const char *old_name;

const char *new_name = NULL;

struct ether_addr generated_mac;

struct ether_addr *mac = NULL;

bool respect_predictable = false;

int r, ifindex;

assert(ctx);

assert(config);

assert(device);

assert(name);

old_name = udev_device_get_sysname(device);

if (!old_name)

return -EINVAL;

r = ethtool_set_speed(&ctx->ethtool_fd, old_name, config->speed / 1024, config->duplex);

if (r < 0)

log_warning_errno(r, "Could not set speed or duplex of %s to %zu Mbps (%s): %m",

old_name, config->speed / 1024,

duplex_to_string(config->duplex));

r = ethtool_set_wol(&ctx->ethtool_fd, old_name, config->wol);

if (r < 0)

log_warning_errno(r, "Could not set WakeOnLan of %s to %s: %m",

old_name, wol_to_string(config->wol));

ifindex = udev_device_get_ifindex(device);

if (ifindex <= 0) {

log_warning("Could not find ifindex");

return -ENODEV;

}

if (ctx->enable_name_policy && config->name_policy) {

NamePolicy *policy;

for (policy = config->name_policy;

!new_name && *policy != _NAMEPOLICY_INVALID; policy++) {

switch (*policy) {

case NAMEPOLICY_KERNEL:

respect_predictable = true;

break;

case NAMEPOLICY_DATABASE:

new_name = udev_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE");

break;

case NAMEPOLICY_ONBOARD:

new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");

break;

case NAMEPOLICY_SLOT:

new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");

break;

case NAMEPOLICY_PATH:

new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");

break;

case NAMEPOLICY_MAC:

new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");

break;

default:

break;

}

}

}

if (should_rename(device, respect_predictable)) {

/* if not set by policy, fall back manually set name */

if (!new_name)

new_name = config->name;

} else

new_name = NULL;

switch (config->mac_policy) {

case MACPOLICY_PERSISTENT:

if (mac_is_random(device)) {

r = get_mac(device, false, &generated_mac);

if (r == -ENOENT) {

log_warning_errno(r, "Could not generate persistent MAC address for %s: %m", old_name);

break;

} else if (r < 0)

return r;

mac = &generated_mac;

}

break;

case MACPOLICY_RANDOM:

if (!mac_is_random(device)) {

r = get_mac(device, true, &generated_mac);

if (r == -ENOENT) {

log_warning_errno(r, "Could not generate random MAC address for %s: %m", old_name);

break;

} else if (r < 0)

return r;

mac = &generated_mac;

}

break;

case MACPOLICY_NONE:

default:

mac = config->mac;

}

r = rtnl_set_link_properties(&ctx->rtnl, ifindex, config->alias, mac, config->mtu);

if (r < 0)

return log_warning_errno(r, "Could not set Alias, MACAddress or MTU on %s: %m", old_name);

*name = new_name;

return 0;

}

int link_get_driver(link_config_ctx *ctx, struct udev_device *device, char **ret) {

const char *name;

char *driver = NULL;

int r;

name = udev_device_get_sysname(device);

if (!name)

return -EINVAL;

r = ethtool_get_driver(&ctx->ethtool_fd, name, &driver);

if (r < 0)

return r;

*ret = driver;

return 0;

}

static const char* const mac_policy_table[_MACPOLICY_MAX] = {

[MACPOLICY_PERSISTENT] = "persistent",

[MACPOLICY_RANDOM] = "random",

[MACPOLICY_NONE] = "none"

};

DEFINE_STRING_TABLE_LOOKUP(mac_policy, MACPolicy);

DEFINE_CONFIG_PARSE_ENUM(config_parse_mac_policy, mac_policy, MACPolicy,

"Failed to parse MAC address policy");

static const char* const name_policy_table[_NAMEPOLICY_MAX] = {

[NAMEPOLICY_KERNEL] = "kernel",

[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");