src/udev/net/link-config.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4  This file is part of systemd.
   5
   6  Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <netinet/ether.h>
  23 #include <linux/netdevice.h>
  24
  25 #include "sd-netlink.h"
  26
  27 #include "alloc-util.h"
  28 #include "conf-files.h"
  29 #include "conf-parser.h"
  30 #include "ethtool-util.h"
  31 #include "fd-util.h"
  32 #include "libudev-private.h"
  33 #include "link-config.h"
  34 #include "log.h"
  35 #include "missing.h"
  36 #include "netlink-util.h"
  37 #include "network-internal.h"
  38 #include "parse-util.h"
  39 #include "path-util.h"
  40 #include "proc-cmdline.h"
  41 #include "random-util.h"
  42 #include "stat-util.h"
  43 #include "string-table.h"
  44 #include "string-util.h"
  45 #include "strv.h"
  46 #include "util.h"
  47
  48 struct link_config_ctx {
  49         LIST_HEAD(link_config, links);
  50
  51         int ethtool_fd;
  52
  53         bool enable_name_policy;
  54
  55         sd_netlink *rtnl;
  56
  57         usec_t link_dirs_ts_usec;
  58 };
  59
  60 static const char* const link_dirs[] = {
  61         "/etc/systemd/network",
  62         "/run/systemd/network",
  63         "/usr/lib/systemd/network",
  64 #ifdef HAVE_SPLIT_USR
  65         "/lib/systemd/network",
  66 #endif
  67         NULL};
  68
  69 static void link_config_free(link_config *link) {
  70         if (!link)
  71                 return;
  72
  73         free(link->filename);
  74
  75         free(link->match_mac);
  76         strv_free(link->match_path);
  77         strv_free(link->match_driver);
  78         strv_free(link->match_type);
  79         free(link->match_name);
  80         free(link->match_host);
  81         free(link->match_virt);
  82         free(link->match_kernel);
  83         free(link->match_arch);
  84
  85         free(link->description);
  86         free(link->mac);
  87         free(link->name_policy);
  88         free(link->name);
  89         free(link->alias);
  90
  91         free(link);
  92 }
  93
  94 DEFINE_TRIVIAL_CLEANUP_FUNC(link_config*, link_config_free);
  95
  96 static void link_configs_free(link_config_ctx *ctx) {
  97         link_config *link, *link_next;
  98
  99         if (!ctx)
 100                 return;
 101
 102         LIST_FOREACH_SAFE(links, link, link_next, ctx->links)
 103                 link_config_free(link);
 104 }
 105
 106 void link_config_ctx_free(link_config_ctx *ctx) {
 107         if (!ctx)
 108                 return;
 109
 110         safe_close(ctx->ethtool_fd);
 111
 112         sd_netlink_unref(ctx->rtnl);
 113
 114         link_configs_free(ctx);
 115
 116         free(ctx);
 117
 118         return;
 119 }
 120
 121 DEFINE_TRIVIAL_CLEANUP_FUNC(link_config_ctx*, link_config_ctx_free);
 122
 123 int link_config_ctx_new(link_config_ctx **ret) {
 124         _cleanup_(link_config_ctx_freep) link_config_ctx *ctx = NULL;
 125
 126         if (!ret)
 127                 return -EINVAL;
 128
 129         ctx = new0(link_config_ctx, 1);
 130         if (!ctx)
 131                 return -ENOMEM;
 132
 133         LIST_HEAD_INIT(ctx->links);
 134
 135         ctx->ethtool_fd = -1;
 136
 137         ctx->enable_name_policy = true;
 138
 139         *ret = ctx;
 140         ctx = NULL;
 141
 142         return 0;
 143 }
 144
 145 static int load_link(link_config_ctx *ctx, const char *filename) {
 146         _cleanup_(link_config_freep) link_config *link = NULL;
 147         _cleanup_fclose_ FILE *file = NULL;
 148         int r;
 149
 150         assert(ctx);
 151         assert(filename);
 152
 153         file = fopen(filename, "re");
 154         if (!file) {
 155                 if (errno == ENOENT)
 156                         return 0;
 157                 else
 158                         return -errno;
 159         }
 160
 161         if (null_or_empty_fd(fileno(file))) {
 162                 log_debug("Skipping empty file: %s", filename);
 163                 return 0;
 164         }
 165
 166         link = new0(link_config, 1);
 167         if (!link)
 168                 return log_oom();
 169
 170         link->mac_policy = _MACPOLICY_INVALID;
 171         link->wol = _WOL_INVALID;
 172         link->duplex = _DUP_INVALID;
 173
 174         r = config_parse(NULL, filename, file,
 175                          "Match\0Link\0Ethernet\0",
 176                          config_item_perf_lookup, link_config_gperf_lookup,
 177                          false, false, true, link);
 178         if (r < 0)
 179                 return r;
 180         else
 181                 log_debug("Parsed configuration file %s", filename);
 182
 183         if (link->mtu > UINT_MAX || link->speed > UINT_MAX)
 184                 return -ERANGE;
 185
 186         link->filename = strdup(filename);
 187
 188         LIST_PREPEND(links, ctx->links, link);
 189         link = NULL;
 190
 191         return 0;
 192 }
 193
 194 static bool enable_name_policy(void) {
 195         _cleanup_free_ char *line = NULL;
 196         const char *word, *state;
 197         int r;
 198         size_t l;
 199
 200         r = proc_cmdline(&line);
 201         if (r < 0) {
 202                 log_warning_errno(r, "Failed to read /proc/cmdline, ignoring: %m");
 203                 return true;
 204         }
 205
 206         FOREACH_WORD_QUOTED(word, l, line, state)
 207                 if (strneq(word, "net.ifnames=0", l))
 208                         return false;
 209
 210         return true;
 211 }
 212
 213 int link_config_load(link_config_ctx *ctx) {
 214         int r;
 215         _cleanup_strv_free_ char **files;
 216         char **f;
 217
 218         link_configs_free(ctx);
 219
 220         if (!enable_name_policy()) {
 221                 ctx->enable_name_policy = false;
 222                 log_info("Network interface NamePolicy= disabled on kernel command line, ignoring.");
 223         }
 224
 225         /* update timestamp */
 226         paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, true);
 227
 228         r = conf_files_list_strv(&files, ".link", NULL, link_dirs);
 229         if (r < 0)
 230                 return log_error_errno(r, "failed to enumerate link files: %m");
 231
 232         STRV_FOREACH_BACKWARDS(f, files) {
 233                 r = load_link(ctx, *f);
 234                 if (r < 0)
 235                         return r;
 236         }
 237
 238         return 0;
 239 }
 240
 241 bool link_config_should_reload(link_config_ctx *ctx) {
 242         return paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, false);
 243 }
 244
 245 int link_config_get(link_config_ctx *ctx, struct udev_device *device,
 246                     link_config **ret) {
 247         link_config *link;
 248
 249         assert(ctx);
 250         assert(device);
 251         assert(ret);
 252
 253         LIST_FOREACH(links, link, ctx->links) {
 254                 const char* attr_value;
 255
 256                 attr_value = udev_device_get_sysattr_value(device, "address");
 257
 258                 if (net_match_config(link->match_mac, link->match_path, link->match_driver,
 259                                      link->match_type, link->match_name, link->match_host,
 260                                      link->match_virt, link->match_kernel, link->match_arch,
 261                                      attr_value ? ether_aton(attr_value) : NULL,
 262                                      udev_device_get_property_value(device, "ID_PATH"),
 263                                      udev_device_get_driver(udev_device_get_parent(device)),
 264                                      udev_device_get_property_value(device, "ID_NET_DRIVER"),
 265                                      udev_device_get_devtype(device),
 266                                      udev_device_get_sysname(device))) {
 267                         if (link->match_name) {
 268                                 unsigned char name_assign_type = NET_NAME_UNKNOWN;
 269
 270                                 attr_value = udev_device_get_sysattr_value(device, "name_assign_type");
 271                                 if (attr_value)
 272                                         (void) safe_atou8(attr_value, &name_assign_type);
 273
 274                                 if (name_assign_type == NET_NAME_ENUM) {
 275                                         log_warning("Config file %s applies to device based on potentially unpredictable interface name '%s'",
 276                                                   link->filename, udev_device_get_sysname(device));
 277                                         *ret = link;
 278
 279                                         return 0;
 280                                 } else if (name_assign_type == NET_NAME_RENAMED) {
 281                                         log_warning("Config file %s matches device based on renamed interface name '%s', ignoring",
 282                                                   link->filename, udev_device_get_sysname(device));
 283
 284                                         continue;
 285                                 }
 286                         }
 287
 288                         log_debug("Config file %s applies to device %s",
 289                                   link->filename,  udev_device_get_sysname(device));
 290
 291                         *ret = link;
 292
 293                         return 0;
 294                 }
 295         }
 296
 297         *ret = NULL;
 298
 299         return -ENOENT;
 300 }
 301
 302 static bool mac_is_random(struct udev_device *device) {
 303         const char *s;
 304         unsigned type;
 305         int r;
 306
 307         /* if we can't get the assign type, assume it is not random */
 308         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 309         if (!s)
 310                 return false;
 311
 312         r = safe_atou(s, &type);
 313         if (r < 0)
 314                 return false;
 315
 316         return type == NET_ADDR_RANDOM;
 317 }
 318
 319 static bool should_rename(struct udev_device *device, bool respect_predictable) {
 320         const char *s;
 321         unsigned type;
 322         int r;
 323
 324         /* if we can't get the assgin type, assume we should rename */
 325         s = udev_device_get_sysattr_value(device, "name_assign_type");
 326         if (!s)
 327                 return true;
 328
 329         r = safe_atou(s, &type);
 330         if (r < 0)
 331                 return true;
 332
 333         switch (type) {
 334         case NET_NAME_USER:
 335         case NET_NAME_RENAMED:
 336                 /* these were already named by userspace, do not touch again */
 337                 return false;
 338         case NET_NAME_PREDICTABLE:
 339                 /* the kernel claims to have given a predictable name */
 340                 if (respect_predictable)
 341                         return false;
 342                 /* fall through */
 343         case NET_NAME_ENUM:
 344         default:
 345                 /* the name is known to be bad, or of an unknown type */
 346                 return true;
 347         }
 348 }
 349
 350 static int get_mac(struct udev_device *device, bool want_random,
 351                    struct ether_addr *mac) {
 352         int r;
 353
 354         if (want_random)
 355                 random_bytes(mac->ether_addr_octet, ETH_ALEN);
 356         else {
 357                 uint8_t result[8];
 358
 359                 r = net_get_unique_predictable_data(device, result);
 360                 if (r < 0)
 361                         return r;
 362
 363                 assert_cc(ETH_ALEN <= sizeof(result));
 364                 memcpy(mac->ether_addr_octet, result, ETH_ALEN);
 365         }
 366
 367         /* see eth_random_addr in the kernel */
 368         mac->ether_addr_octet[0] &= 0xfe;  /* clear multicast bit */
 369         mac->ether_addr_octet[0] |= 0x02;  /* set local assignment bit (IEEE802) */
 370
 371         return 0;
 372 }
 373
 374 int link_config_apply(link_config_ctx *ctx, link_config *config,
 375                       struct udev_device *device, const char **name) {
 376         const char *old_name;
 377         const char *new_name = NULL;
 378         struct ether_addr generated_mac;
 379         struct ether_addr *mac = NULL;
 380         bool respect_predictable = false;
 381         int r, ifindex;
 382
 383         assert(ctx);
 384         assert(config);
 385         assert(device);
 386         assert(name);
 387
 388         old_name = udev_device_get_sysname(device);
 389         if (!old_name)
 390                 return -EINVAL;
 391
 392         r = ethtool_set_speed(&ctx->ethtool_fd, old_name, config->speed / 1024, config->duplex);
 393         if (r < 0)
 394                 log_warning_errno(r, "Could not set speed or duplex of %s to %zu Mbps (%s): %m",
 395                                   old_name, config->speed / 1024,
 396                                   duplex_to_string(config->duplex));
 397
 398         r = ethtool_set_wol(&ctx->ethtool_fd, old_name, config->wol);
 399         if (r < 0)
 400                 log_warning_errno(r, "Could not set WakeOnLan of %s to %s: %m",
 401                                   old_name, wol_to_string(config->wol));
 402
 403         ifindex = udev_device_get_ifindex(device);
 404         if (ifindex <= 0) {
 405                 log_warning("Could not find ifindex");
 406                 return -ENODEV;
 407         }
 408
 409         if (ctx->enable_name_policy && config->name_policy) {
 410                 NamePolicy *policy;
 411
 412                 for (policy = config->name_policy;
 413                      !new_name && *policy != _NAMEPOLICY_INVALID; policy++) {
 414                         switch (*policy) {
 415                                 case NAMEPOLICY_KERNEL:
 416                                         respect_predictable = true;
 417                                         break;
 418                                 case NAMEPOLICY_DATABASE:
 419                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE");
 420                                         break;
 421                                 case NAMEPOLICY_ONBOARD:
 422                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 423                                         break;
 424                                 case NAMEPOLICY_SLOT:
 425                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 426                                         break;
 427                                 case NAMEPOLICY_PATH:
 428                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 429                                         break;
 430                                 case NAMEPOLICY_MAC:
 431                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");
 432                                         break;
 433                                 default:
 434                                         break;
 435                         }
 436                 }
 437         }
 438
 439         if (should_rename(device, respect_predictable)) {
 440                 /* if not set by policy, fall back manually set name */
 441                 if (!new_name)
 442                         new_name = config->name;
 443         } else
 444                 new_name = NULL;
 445
 446         switch (config->mac_policy) {
 447                 case MACPOLICY_PERSISTENT:
 448                         if (mac_is_random(device)) {
 449                                 r = get_mac(device, false, &generated_mac);
 450                                 if (r == -ENOENT) {
 451                                         log_warning_errno(r, "Could not generate persistent MAC address for %s: %m", old_name);
 452                                         break;
 453                                 } else if (r < 0)
 454                                         return r;
 455                                 mac = &generated_mac;
 456                         }
 457                         break;
 458                 case MACPOLICY_RANDOM:
 459                         if (!mac_is_random(device)) {
 460                                 r = get_mac(device, true, &generated_mac);
 461                                 if (r == -ENOENT) {
 462                                         log_warning_errno(r, "Could not generate random MAC address for %s: %m", old_name);
 463                                         break;
 464                                 } else if (r < 0)
 465                                         return r;
 466                                 mac = &generated_mac;
 467                         }
 468                         break;
 469                 case MACPOLICY_NONE:
 470                 default:
 471                         mac = config->mac;
 472         }
 473
 474         r = rtnl_set_link_properties(&ctx->rtnl, ifindex, config->alias, mac, config->mtu);
 475         if (r < 0)
 476                 return log_warning_errno(r, "Could not set Alias, MACAddress or MTU on %s: %m", old_name);
 477
 478         *name = new_name;
 479
 480         return 0;
 481 }
 482
 483 int link_get_driver(link_config_ctx *ctx, struct udev_device *device, char **ret) {
 484         const char *name;
 485         char *driver = NULL;
 486         int r;
 487
 488         name = udev_device_get_sysname(device);
 489         if (!name)
 490                 return -EINVAL;
 491
 492         r = ethtool_get_driver(&ctx->ethtool_fd, name, &driver);
 493         if (r < 0)
 494                 return r;
 495
 496         *ret = driver;
 497         return 0;
 498 }
 499
 500 static const char* const mac_policy_table[_MACPOLICY_MAX] = {
 501         [MACPOLICY_PERSISTENT] = "persistent",
 502         [MACPOLICY_RANDOM] = "random",
 503         [MACPOLICY_NONE] = "none"
 504 };
 505
 506 DEFINE_STRING_TABLE_LOOKUP(mac_policy, MACPolicy);
 507 DEFINE_CONFIG_PARSE_ENUM(config_parse_mac_policy, mac_policy, MACPolicy,
 508                          "Failed to parse MAC address policy");
 509
 510 static const char* const name_policy_table[_NAMEPOLICY_MAX] = {
 511         [NAMEPOLICY_KERNEL] = "kernel",
 512         [NAMEPOLICY_DATABASE] = "database",
 513         [NAMEPOLICY_ONBOARD] = "onboard",
 514         [NAMEPOLICY_SLOT] = "slot",
 515         [NAMEPOLICY_PATH] = "path",
 516         [NAMEPOLICY_MAC] = "mac"
 517 };
 518
 519 DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
 520 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy,
 521                           _NAMEPOLICY_INVALID,
 522                           "Failed to parse interface name policy");