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-id128.h"
  26
  27 #include "missing.h"
  28 #include "link-config.h"
  29 #include "ethtool-util.h"
  30
  31 #include "libudev-private.h"
  32 #include "sd-rtnl.h"
  33 #include "util.h"
  34 #include "log.h"
  35 #include "strv.h"
  36 #include "path-util.h"
  37 #include "conf-parser.h"
  38 #include "conf-files.h"
  39 #include "fileio.h"
  40 #include "hashmap.h"
  41 #include "rtnl-util.h"
  42 #include "network-internal.h"
  43 #include "siphash24.h"
  44
  45 struct link_config_ctx {
  46         LIST_HEAD(link_config, links);
  47
  48         int ethtool_fd;
  49
  50         bool enable_name_policy;
  51
  52         sd_rtnl *rtnl;
  53
  54         usec_t link_dirs_ts_usec;
  55 };
  56
  57 static const char* const link_dirs[] = {
  58         "/etc/systemd/network",
  59         "/run/systemd/network",
  60         "/usr/lib/systemd/network",
  61 #ifdef HAVE_SPLIT_USR
  62         "/lib/systemd/network",
  63 #endif
  64         NULL};
  65
  66 DEFINE_TRIVIAL_CLEANUP_FUNC(link_config_ctx*, link_config_ctx_free);
  67 #define _cleanup_link_config_ctx_free_ _cleanup_(link_config_ctx_freep)
  68
  69 int link_config_ctx_new(link_config_ctx **ret) {
  70         _cleanup_link_config_ctx_free_ link_config_ctx *ctx = NULL;
  71
  72         if (!ret)
  73                 return -EINVAL;
  74
  75         ctx = new0(link_config_ctx, 1);
  76         if (!ctx)
  77                 return -ENOMEM;
  78
  79         LIST_HEAD_INIT(ctx->links);
  80
  81         ctx->ethtool_fd = -1;
  82
  83         ctx->enable_name_policy = true;
  84
  85         *ret = ctx;
  86         ctx = NULL;
  87
  88         return 0;
  89 }
  90
  91 static void link_configs_free(link_config_ctx *ctx) {
  92         link_config *link, *link_next;
  93
  94         if (!ctx)
  95                 return;
  96
  97         LIST_FOREACH_SAFE(links, link, link_next, ctx->links) {
  98                 free(link->filename);
  99                 free(link->name);
 100                 free(link->match_path);
 101                 free(link->match_driver);
 102                 free(link->match_type);
 103                 free(link->description);
 104                 free(link->alias);
 105                 free(link->name_policy);
 106
 107                 free(link);
 108         }
 109 }
 110
 111 void link_config_ctx_free(link_config_ctx *ctx) {
 112         if (!ctx)
 113                 return;
 114
 115         safe_close(ctx->ethtool_fd);
 116
 117         sd_rtnl_unref(ctx->rtnl);
 118
 119         link_configs_free(ctx);
 120
 121         free(ctx);
 122
 123         return;
 124 }
 125
 126 static int load_link(link_config_ctx *ctx, const char *filename) {
 127         _cleanup_free_ link_config *link = NULL;
 128         _cleanup_fclose_ FILE *file = NULL;
 129         int r;
 130
 131         assert(ctx);
 132         assert(filename);
 133
 134         file = fopen(filename, "re");
 135         if (!file) {
 136                 if (errno == ENOENT)
 137                         return 0;
 138                 else
 139                         return -errno;
 140         }
 141
 142         if (null_or_empty_fd(fileno(file))) {
 143                 log_debug("Skipping empty file: %s", filename);
 144                 return 0;
 145         }
 146
 147         link = new0(link_config, 1);
 148         if (!link)
 149                 return log_oom();
 150
 151         link->mac_policy = _MACPOLICY_INVALID;
 152         link->wol = _WOL_INVALID;
 153         link->duplex = _DUP_INVALID;
 154
 155         r = config_parse(NULL, filename, file,
 156                          "Match\0Link\0Ethernet\0",
 157                          config_item_perf_lookup, link_config_gperf_lookup,
 158                          false, false, true, link);
 159         if (r < 0)
 160                 return r;
 161         else
 162                 log_debug("Parsed configuration file %s", filename);
 163
 164         link->filename = strdup(filename);
 165
 166         LIST_PREPEND(links, ctx->links, link);
 167         link = NULL;
 168
 169         return 0;
 170 }
 171
 172 static bool enable_name_policy(void) {
 173         _cleanup_free_ char *line = NULL;
 174         const char *word, *state;
 175         int r;
 176         size_t l;
 177
 178         r = proc_cmdline(&line);
 179         if (r < 0) {
 180                 log_warning_errno(r, "Failed to read /proc/cmdline, ignoring: %m");
 181                 return true;
 182         }
 183
 184         FOREACH_WORD_QUOTED(word, l, line, state)
 185                 if (strneq(word, "net.ifnames=0", l))
 186                         return false;
 187
 188         return true;
 189 }
 190
 191 int link_config_load(link_config_ctx *ctx) {
 192         int r;
 193         _cleanup_strv_free_ char **files;
 194         char **f;
 195
 196         link_configs_free(ctx);
 197
 198         if (!enable_name_policy()) {
 199                 ctx->enable_name_policy = false;
 200                 log_info("Network interface NamePolicy= disabled on kernel command line, ignoring.");
 201         }
 202
 203         /* update timestamp */
 204         paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, true);
 205
 206         r = conf_files_list_strv(&files, ".link", NULL, link_dirs);
 207         if (r < 0)
 208                 return log_error_errno(r, "failed to enumerate link files: %m");
 209
 210         STRV_FOREACH_BACKWARDS(f, files) {
 211                 r = load_link(ctx, *f);
 212                 if (r < 0)
 213                         return r;
 214         }
 215
 216         return 0;
 217 }
 218
 219 bool link_config_should_reload(link_config_ctx *ctx) {
 220         return paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, false);
 221 }
 222
 223 int link_config_get(link_config_ctx *ctx, struct udev_device *device,
 224                     link_config **ret) {
 225         link_config *link;
 226
 227         LIST_FOREACH(links, link, ctx->links) {
 228                 const char* attr_value;
 229
 230                 attr_value = udev_device_get_sysattr_value(device, "address");
 231
 232                 if (net_match_config(link->match_mac, link->match_path, link->match_driver,
 233                                      link->match_type, link->match_name, link->match_host,
 234                                      link->match_virt, link->match_kernel, link->match_arch,
 235                                      attr_value ? ether_aton(attr_value) : NULL,
 236                                      udev_device_get_property_value(device, "ID_PATH"),
 237                                      udev_device_get_driver(udev_device_get_parent(device)),
 238                                      udev_device_get_property_value(device, "ID_NET_DRIVER"),
 239                                      udev_device_get_devtype(device),
 240                                      udev_device_get_sysname(device))) {
 241                         if (link->match_name) {
 242                                 unsigned char name_assign_type = NET_NAME_UNKNOWN;
 243
 244                                 attr_value = udev_device_get_sysattr_value(device, "name_assign_type");
 245                                 if (attr_value)
 246                                         (void)safe_atou8(attr_value, &name_assign_type);
 247
 248                                 if (name_assign_type == NET_NAME_ENUM) {
 249                                         log_warning("Config file %s applies to device based on potentially unpredictable interface name '%s'",
 250                                                   link->filename, udev_device_get_sysname(device));
 251                                         *ret = link;
 252
 253                                         return 0;
 254                                 } else if (name_assign_type == NET_NAME_RENAMED) {
 255                                         log_warning("Config file %s matches device based on renamed interface name '%s', ignoring",
 256                                                   link->filename, udev_device_get_sysname(device));
 257
 258                                         continue;
 259                                 }
 260                         }
 261
 262                         log_debug("Config file %s applies to device %s",
 263                                   link->filename,  udev_device_get_sysname(device));
 264
 265                         *ret = link;
 266
 267                         return 0;
 268                 }
 269         }
 270
 271         *ret = NULL;
 272
 273         return -ENOENT;
 274 }
 275
 276 static bool mac_is_random(struct udev_device *device) {
 277         const char *s;
 278         unsigned type;
 279         int r;
 280
 281         /* if we can't get the assign type, assume it is not random */
 282         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 283         if (!s)
 284                 return false;
 285
 286         r = safe_atou(s, &type);
 287         if (r < 0)
 288                 return false;
 289
 290         return type == NET_ADDR_RANDOM;
 291 }
 292
 293 static bool should_rename(struct udev_device *device, bool respect_predictable) {
 294         const char *s;
 295         unsigned type;
 296         int r;
 297
 298         /* if we can't get the assgin type, assume we should rename */
 299         s = udev_device_get_sysattr_value(device, "name_assign_type");
 300         if (!s)
 301                 return true;
 302
 303         r = safe_atou(s, &type);
 304         if (r < 0)
 305                 return true;
 306
 307         switch (type) {
 308         case NET_NAME_USER:
 309         case NET_NAME_RENAMED:
 310                 /* these were already named by userspace, do not touch again */
 311                 return false;
 312         case NET_NAME_PREDICTABLE:
 313                 /* the kernel claims to have given a predictable name */
 314                 if (respect_predictable)
 315                         return false;
 316                 /* fall through */
 317         case NET_NAME_ENUM:
 318         default:
 319                 /* the name is known to be bad, or of an unknown type */
 320                 return true;
 321         }
 322 }
 323
 324 static int get_mac(struct udev_device *device, bool want_random,
 325                    struct ether_addr *mac) {
 326         int r;
 327
 328         if (want_random)
 329                 random_bytes(mac->ether_addr_octet, ETH_ALEN);
 330         else {
 331                 uint8_t result[8];
 332
 333                 r = net_get_unique_predictable_data(device, result);
 334                 if (r < 0)
 335                         return r;
 336
 337                 assert_cc(ETH_ALEN <= sizeof(result));
 338                 memcpy(mac->ether_addr_octet, result, ETH_ALEN);
 339         }
 340
 341         /* see eth_random_addr in the kernel */
 342         mac->ether_addr_octet[0] &= 0xfe;  /* clear multicast bit */
 343         mac->ether_addr_octet[0] |= 0x02;  /* set local assignment bit (IEEE802) */
 344
 345         return 0;
 346 }
 347
 348 int link_config_apply(link_config_ctx *ctx, link_config *config,
 349                       struct udev_device *device, const char **name) {
 350         const char *old_name;
 351         const char *new_name = NULL;
 352         struct ether_addr generated_mac;
 353         struct ether_addr *mac = NULL;
 354         bool respect_predictable = false;
 355         int r, ifindex;
 356
 357         assert(ctx);
 358         assert(config);
 359         assert(device);
 360         assert(name);
 361
 362         old_name = udev_device_get_sysname(device);
 363         if (!old_name)
 364                 return -EINVAL;
 365
 366         r = ethtool_set_speed(&ctx->ethtool_fd, old_name, config->speed / 1024,
 367                               config->duplex);
 368         if (r < 0)
 369                 log_warning_errno(r, "Could not set speed or duplex of %s to %u Mbps (%s): %m",
 370                                   old_name, config->speed / 1024,
 371                                   duplex_to_string(config->duplex));
 372
 373         r = ethtool_set_wol(&ctx->ethtool_fd, old_name, config->wol);
 374         if (r < 0)
 375                 log_warning_errno(r, "Could not set WakeOnLan of %s to %s: %m",
 376                                   old_name, wol_to_string(config->wol));
 377
 378         ifindex = udev_device_get_ifindex(device);
 379         if (ifindex <= 0) {
 380                 log_warning("Could not find ifindex");
 381                 return -ENODEV;
 382         }
 383
 384         if (ctx->enable_name_policy && config->name_policy) {
 385                 NamePolicy *policy;
 386
 387                 for (policy = config->name_policy;
 388                      !new_name && *policy != _NAMEPOLICY_INVALID; policy++) {
 389                         switch (*policy) {
 390                                 case NAMEPOLICY_KERNEL:
 391                                         respect_predictable = true;
 392                                         break;
 393                                 case NAMEPOLICY_DATABASE:
 394                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE");
 395                                         break;
 396                                 case NAMEPOLICY_ONBOARD:
 397                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 398                                         break;
 399                                 case NAMEPOLICY_SLOT:
 400                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 401                                         break;
 402                                 case NAMEPOLICY_PATH:
 403                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 404                                         break;
 405                                 case NAMEPOLICY_MAC:
 406                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");
 407                                         break;
 408                                 default:
 409                                         break;
 410                         }
 411                 }
 412         }
 413
 414         if (should_rename(device, respect_predictable)) {
 415                 /* if not set by policy, fall back manually set name */
 416                 if (!new_name)
 417                         new_name = config->name;
 418         } else
 419                 new_name = NULL;
 420
 421         switch (config->mac_policy) {
 422                 case MACPOLICY_PERSISTENT:
 423                         if (mac_is_random(device)) {
 424                                 r = get_mac(device, false, &generated_mac);
 425                                 if (r == -ENOENT)
 426                                         break;
 427                                 else if (r < 0)
 428                                         return r;
 429                                 mac = &generated_mac;
 430                         }
 431                         break;
 432                 case MACPOLICY_RANDOM:
 433                         if (!mac_is_random(device)) {
 434                                 r = get_mac(device, true, &generated_mac);
 435                                 if (r == -ENOENT)
 436                                         break;
 437                                 else if (r < 0)
 438                                         return r;
 439                                 mac = &generated_mac;
 440                         }
 441                         break;
 442                 default:
 443                         mac = config->mac;
 444         }
 445
 446         r = rtnl_set_link_properties(&ctx->rtnl, ifindex, config->alias, mac,
 447                                      config->mtu);
 448         if (r < 0)
 449                 return log_warning_errno(r, "Could not set Alias, MACAddress or MTU on %s: %m", old_name);
 450
 451         *name = new_name;
 452
 453         return 0;
 454 }
 455
 456 int link_get_driver(link_config_ctx *ctx, struct udev_device *device, char **ret) {
 457         const char *name;
 458         char *driver;
 459         int r;
 460
 461         name = udev_device_get_sysname(device);
 462         if (!name)
 463                 return -EINVAL;
 464
 465         r = ethtool_get_driver(&ctx->ethtool_fd, name, &driver);
 466         if (r < 0)
 467                 return r;
 468
 469         *ret = driver;
 470         return 0;
 471 }
 472
 473 static const char* const mac_policy_table[_MACPOLICY_MAX] = {
 474         [MACPOLICY_PERSISTENT] = "persistent",
 475         [MACPOLICY_RANDOM] = "random"
 476 };
 477
 478 DEFINE_STRING_TABLE_LOOKUP(mac_policy, MACPolicy);
 479 DEFINE_CONFIG_PARSE_ENUM(config_parse_mac_policy, mac_policy, MACPolicy,
 480                          "Failed to parse MAC address policy");
 481
 482 static const char* const name_policy_table[_NAMEPOLICY_MAX] = {
 483         [NAMEPOLICY_KERNEL] = "kernel",
 484         [NAMEPOLICY_DATABASE] = "database",
 485         [NAMEPOLICY_ONBOARD] = "onboard",
 486         [NAMEPOLICY_SLOT] = "slot",
 487         [NAMEPOLICY_PATH] = "path",
 488         [NAMEPOLICY_MAC] = "mac"
 489 };
 490
 491 DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
 492 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy,
 493                           _NAMEPOLICY_INVALID,
 494                           "Failed to parse interface name policy");