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 int link_config_ctx_connect(link_config_ctx *ctx) {
  92         int r;
  93
  94         if (ctx->ethtool_fd == -1) {
  95                 r = ethtool_connect(&ctx->ethtool_fd);
  96                 if (r < 0) {
  97                         log_warning("link_config: could not connect to ethtool: %s",
  98                                     strerror(-r));
  99                         return r;
 100                 }
 101         }
 102
 103         if (!ctx->rtnl) {
 104                 r = sd_rtnl_open(&ctx->rtnl, 0);
 105                 if (r < 0) {
 106                         log_warning("link_config: could not connect to rtnl: %s",
 107                                     strerror(-r));
 108                         return r;
 109                 }
 110         }
 111
 112         return 0;
 113 }
 114
 115 static void link_configs_free(link_config_ctx *ctx) {
 116         link_config *link, *link_next;
 117
 118         if (!ctx)
 119                 return;
 120
 121         LIST_FOREACH_SAFE(links, link, link_next, ctx->links) {
 122                 free(link->filename);
 123                 free(link->match_path);
 124                 free(link->match_driver);
 125                 free(link->match_type);
 126                 free(link->description);
 127                 free(link->alias);
 128                 free(link->name_policy);
 129
 130                 free(link);
 131         }
 132 }
 133
 134 void link_config_ctx_free(link_config_ctx *ctx) {
 135         if (!ctx)
 136                 return;
 137
 138         safe_close(ctx->ethtool_fd);
 139
 140         sd_rtnl_unref(ctx->rtnl);
 141
 142         link_configs_free(ctx);
 143
 144         free(ctx);
 145
 146         return;
 147 }
 148
 149 static int load_link(link_config_ctx *ctx, const char *filename) {
 150         _cleanup_free_ link_config *link = NULL;
 151         _cleanup_fclose_ FILE *file = NULL;
 152         int r;
 153
 154         assert(ctx);
 155         assert(filename);
 156
 157         file = fopen(filename, "re");
 158         if (!file) {
 159                 if (errno == ENOENT)
 160                         return 0;
 161                 else
 162                         return -errno;
 163         }
 164
 165         if (null_or_empty_fd(fileno(file))) {
 166                 log_debug("Skipping empty file: %s", filename);
 167                 return 0;
 168         }
 169
 170         link = new0(link_config, 1);
 171         if (!link)
 172                 return log_oom();
 173
 174         link->mac_policy = _MACPOLICY_INVALID;
 175         link->wol = _WOL_INVALID;
 176         link->duplex = _DUP_INVALID;
 177
 178         r = config_parse(NULL, filename, file,
 179                          "Match\0Link\0Ethernet\0",
 180                          config_item_perf_lookup, link_config_gperf_lookup,
 181                          false, false, true, link);
 182         if (r < 0)
 183                 return r;
 184         else
 185                 log_debug("Parsed configuration file %s", filename);
 186
 187         link->filename = strdup(filename);
 188
 189         LIST_PREPEND(links, ctx->links, link);
 190         link = NULL;
 191
 192         return 0;
 193 }
 194
 195 static bool enable_name_policy(void) {
 196         _cleanup_free_ char *line = NULL;
 197         const char *word, *state;
 198         int r;
 199         size_t l;
 200
 201         r = proc_cmdline(&line);
 202         if (r < 0)
 203                 log_warning("Failed to read /proc/cmdline, ignoring: %s",
 204                             strerror(-r));
 205         if (r <= 0)
 206                 return true;
 207
 208         FOREACH_WORD_QUOTED(word, l, line, state)
 209                 if (strneq(word, "net.ifnames=0", l))
 210                         return false;
 211
 212         return true;
 213 }
 214
 215 int link_config_load(link_config_ctx *ctx) {
 216         int r;
 217         _cleanup_strv_free_ char **files;
 218         char **f;
 219
 220         link_configs_free(ctx);
 221
 222         if (!enable_name_policy()) {
 223                 ctx->enable_name_policy = false;
 224                 log_info("Network interface NamePolicy= disabled on kernel commandline, ignoring.");
 225         }
 226
 227         /* update timestamp */
 228         paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, true);
 229
 230         r = conf_files_list_strv(&files, ".link", NULL, link_dirs);
 231         if (r < 0) {
 232                 log_error("failed to enumerate link files: %s", strerror(-r));
 233                 return r;
 234         }
 235
 236         STRV_FOREACH_BACKWARDS(f, files) {
 237                 r = load_link(ctx, *f);
 238                 if (r < 0)
 239                         return r;
 240         }
 241
 242         return 0;
 243 }
 244
 245 bool link_config_should_reload(link_config_ctx *ctx) {
 246         return paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, false);
 247 }
 248
 249 int link_config_get(link_config_ctx *ctx, struct udev_device *device,
 250                     link_config **ret) {
 251         link_config *link;
 252
 253         LIST_FOREACH(links, link, ctx->links) {
 254
 255                 if (net_match_config(link->match_mac, link->match_path, link->match_driver,
 256                                      link->match_type, NULL, link->match_host,
 257                                      link->match_virt, link->match_kernel, link->match_arch,
 258                                      ether_aton(udev_device_get_sysattr_value(device, "address")),
 259                                      udev_device_get_property_value(device, "ID_PATH"),
 260                                      udev_device_get_driver(udev_device_get_parent(device)),
 261                                      udev_device_get_property_value(device, "ID_NET_DRIVER"),
 262                                      udev_device_get_devtype(device),
 263                                      NULL)) {
 264                         log_debug("Config file %s applies to device %s",
 265                                   link->filename,
 266                                   udev_device_get_sysname(device));
 267                         *ret = link;
 268                         return 0;
 269                 }
 270         }
 271
 272         *ret = NULL;
 273
 274         return -ENOENT;
 275 }
 276
 277 static bool mac_is_random(struct udev_device *device) {
 278         const char *s;
 279         unsigned type;
 280         int r;
 281
 282         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 283         if (!s)
 284                 return false; /* if we don't know, assume it is not random */
 285         r = safe_atou(s, &type);
 286         if (r < 0)
 287                 return false;
 288
 289         return type == NET_ADDR_RANDOM;
 290 }
 291
 292 static bool should_rename(struct udev_device *device, bool respect_predictable) {
 293         const char *s;
 294         unsigned type;
 295         int r;
 296
 297         s = udev_device_get_sysattr_value(device, "name_assign_type");
 298         if (!s)
 299                 return true; /* if we don't know, assume we should rename */
 300         r = safe_atou(s, &type);
 301         if (r < 0)
 302                 return true;
 303
 304         switch (type) {
 305         case NET_NAME_USER:
 306         case NET_NAME_RENAMED:
 307                 return false; /* these were already named by userspace, do not touch again */
 308         case NET_NAME_PREDICTABLE:
 309                 if (respect_predictable)
 310                         return false; /* the kernel claims to have given a predictable name */
 311                 /* fall through */
 312         case NET_NAME_ENUM:
 313         default:
 314                 return true; /* the name is known to be bad, or of an unknown type */
 315         }
 316 }
 317
 318 static int get_mac(struct udev_device *device, bool want_random,
 319                    struct ether_addr *mac) {
 320         int r;
 321
 322         if (want_random)
 323                 random_bytes(mac->ether_addr_octet, ETH_ALEN);
 324         else {
 325                 uint8_t result[8];
 326
 327                 r = net_get_unique_predictable_data(device, result);
 328                 if (r < 0)
 329                         return r;
 330
 331                 assert_cc(ETH_ALEN <= sizeof(result));
 332                 memcpy(mac->ether_addr_octet, result, ETH_ALEN);
 333         }
 334
 335         /* see eth_random_addr in the kernel */
 336         mac->ether_addr_octet[0] &= 0xfe;        /* clear multicast bit */
 337         mac->ether_addr_octet[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 338
 339         return 0;
 340 }
 341
 342 int link_config_apply(link_config_ctx *ctx, link_config *config,
 343                       struct udev_device *device, const char **name) {
 344         const char *old_name;
 345         const char *new_name = NULL;
 346         struct ether_addr generated_mac;
 347         struct ether_addr *mac = NULL;
 348         bool respect_predictable = false;
 349         int r, ifindex;
 350
 351         assert(ctx);
 352         assert(config);
 353         assert(device);
 354         assert(name);
 355
 356         r = link_config_ctx_connect(ctx);
 357         if (r < 0)
 358                 return r;
 359
 360         old_name = udev_device_get_sysname(device);
 361         if (!old_name)
 362                 return -EINVAL;
 363
 364         r = ethtool_set_speed(ctx->ethtool_fd, old_name, config->speed / 1024,
 365                               config->duplex);
 366         if (r < 0)
 367                 log_warning("Could not set speed or duplex of %s to %u Mbps (%s): %s",
 368                             old_name, config->speed / 1024,
 369                             duplex_to_string(config->duplex), strerror(-r));
 370
 371         r = ethtool_set_wol(ctx->ethtool_fd, old_name, config->wol);
 372         if (r < 0)
 373                 log_warning("Could not set WakeOnLan of %s to %s: %s",
 374                             old_name, wol_to_string(config->wol), strerror(-r));
 375
 376         ifindex = udev_device_get_ifindex(device);
 377         if (ifindex <= 0) {
 378                 log_warning("Could not find ifindex");
 379                 return -ENODEV;
 380         }
 381
 382         if (ctx->enable_name_policy && config->name_policy) {
 383                 NamePolicy *policy;
 384
 385                 for (policy = config->name_policy; !respect_predictable && !new_name &&
 386                                                    *policy != _NAMEPOLICY_INVALID; policy++) {
 387                         switch (*policy) {
 388                                 case NAMEPOLICY_KERNEL:
 389                                         respect_predictable = true;
 390                                         break;
 391                                 case NAMEPOLICY_DATABASE:
 392                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE");
 393                                         break;
 394                                 case NAMEPOLICY_ONBOARD:
 395                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 396                                         break;
 397                                 case NAMEPOLICY_SLOT:
 398                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 399                                         break;
 400                                 case NAMEPOLICY_PATH:
 401                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 402                                         break;
 403                                 case NAMEPOLICY_MAC:
 404                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");
 405                                         break;
 406                                 default:
 407                                         break;
 408                         }
 409                 }
 410         }
 411
 412         if (should_rename(device, respect_predictable)) {
 413                 if (!new_name)
 414                         /* if not set by policy, fall back manually set name */
 415                         new_name = config->name;
 416         } else
 417                 new_name = NULL;
 418
 419         *name = new_name;
 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                 log_warning("Could not set Alias, MACAddress or MTU on %s: %s",
 450                             old_name, strerror(-r));
 451                 return r;
 452         }
 453
 454         return 0;
 455 }
 456
 457 int link_get_driver(link_config_ctx *ctx, struct udev_device *device, char **ret) {
 458         const char *name;
 459         char *driver;
 460         int r;
 461
 462         r = link_config_ctx_connect(ctx);
 463         if (r < 0)
 464                 return r;
 465
 466         name = udev_device_get_sysname(device);
 467         if (!name)
 468                 return -EINVAL;
 469
 470         r = ethtool_get_driver(ctx->ethtool_fd, name, &driver);
 471         if (r < 0)
 472                 return r;
 473
 474         *ret = driver;
 475         return 0;
 476 }
 477
 478 static const char* const mac_policy_table[_MACPOLICY_MAX] = {
 479         [MACPOLICY_PERSISTENT] = "persistent",
 480         [MACPOLICY_RANDOM] = "random"
 481 };
 482
 483 DEFINE_STRING_TABLE_LOOKUP(mac_policy, MACPolicy);
 484 DEFINE_CONFIG_PARSE_ENUM(config_parse_mac_policy, mac_policy, MACPolicy,
 485                          "Failed to parse MAC address policy");
 486
 487 static const char* const name_policy_table[_NAMEPOLICY_MAX] = {
 488         [NAMEPOLICY_KERNEL] = "kernel",
 489         [NAMEPOLICY_DATABASE] = "database",
 490         [NAMEPOLICY_ONBOARD] = "onboard",
 491         [NAMEPOLICY_SLOT] = "slot",
 492         [NAMEPOLICY_PATH] = "path",
 493         [NAMEPOLICY_MAC] = "mac"
 494 };
 495
 496 DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
 497 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy,
 498                           _NAMEPOLICY_INVALID,
 499                           "Failed to parse interface name policy");