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 <net/if.h>
  24
  25 #include "sd-id128.h"
  26
  27 #include "link-config.h"
  28 #include "ethtool-util.h"
  29
  30 #include "libudev-private.h"
  31 #include "sd-rtnl.h"
  32 #include "util.h"
  33 #include "log.h"
  34 #include "strv.h"
  35 #include "path-util.h"
  36 #include "conf-parser.h"
  37 #include "conf-files.h"
  38 #include "fileio.h"
  39 #include "hashmap.h"
  40 #include "rtnl-util.h"
  41 #include "net-util.h"
  42
  43 struct link_config_ctx {
  44         LIST_HEAD(link_config, links);
  45
  46         int ethtool_fd;
  47
  48         bool enable_name_policy;
  49
  50         sd_rtnl *rtnl;
  51
  52         char **link_dirs;
  53         usec_t link_dirs_ts_usec;
  54 };
  55
  56 DEFINE_TRIVIAL_CLEANUP_FUNC(link_config_ctx*, link_config_ctx_free);
  57 #define _cleanup_link_config_ctx_free_ _cleanup_(link_config_ctx_freep)
  58
  59 int link_config_ctx_new(link_config_ctx **ret) {
  60         _cleanup_link_config_ctx_free_ link_config_ctx *ctx = NULL;
  61
  62         if (!ret)
  63                 return -EINVAL;
  64
  65         ctx = new0(link_config_ctx, 1);
  66         if (!ctx)
  67                 return -ENOMEM;
  68
  69         LIST_HEAD_INIT(ctx->links);
  70
  71         ctx->ethtool_fd = -1;
  72
  73         ctx->enable_name_policy = true;
  74
  75         ctx->link_dirs = strv_new("/etc/systemd/network",
  76                                   "/run/systemd/network",
  77                                   "/usr/lib/systemd/network",
  78 #ifdef HAVE_SPLIT_USR
  79                                   "/lib/systemd/network",
  80 #endif
  81                                   NULL);
  82         if (!ctx->link_dirs) {
  83                 log_error("failed to build link config directory array");
  84                 return -ENOMEM;
  85         }
  86
  87         if (!path_strv_canonicalize_uniq(ctx->link_dirs)) {
  88                 log_error("failed to canonicalize link config directories\n");
  89                 return -ENOMEM;
  90         }
  91
  92         *ret = ctx;
  93         ctx = NULL;
  94
  95         return 0;
  96 }
  97
  98 static int link_config_ctx_connect(link_config_ctx *ctx) {
  99         int r;
 100
 101         if (ctx->ethtool_fd >= 0 && ctx->rtnl)
 102                 return 0;
 103
 104         r = ethtool_connect(&ctx->ethtool_fd);
 105         if (r < 0)
 106                 return r;
 107
 108         r = sd_rtnl_open(0, &ctx->rtnl);
 109         if (r < 0)
 110                 return r;
 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
 128                 free(link);
 129         }
 130 }
 131
 132 void link_config_ctx_free(link_config_ctx *ctx) {
 133         if (!ctx)
 134                 return;
 135
 136         if (ctx->ethtool_fd >= 0)
 137                 close_nointr_nofail(ctx->ethtool_fd);
 138
 139         sd_rtnl_unref(ctx->rtnl);
 140
 141         strv_free(ctx->link_dirs);
 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         link_config *link;
 151         FILE *file;
 152         int r;
 153
 154         file = fopen(filename, "re");
 155         if (!file) {
 156                 if (errno == ENOENT)
 157                         return 0;
 158                 else
 159                         return errno;
 160         }
 161
 162         link = new0(link_config, 1);
 163         if (!link) {
 164                 r = log_oom();
 165                 goto failure;
 166         }
 167
 168         link->mac_policy = _MACPOLICY_INVALID;
 169         link->wol = _WOL_INVALID;
 170         link->duplex = _DUP_INVALID;
 171
 172
 173         r = config_parse(NULL, filename, file, "Match\0Link\0Ethernet\0", config_item_perf_lookup,
 174                          (void*) link_config_gperf_lookup, false, false, link);
 175         if (r < 0) {
 176                 log_warning("Colud not parse config file %s: %s", filename, strerror(-r));
 177                 goto failure;
 178         } else
 179                 log_debug("Parsed configuration file %s", filename);
 180
 181         link->filename = strdup(filename);
 182
 183         LIST_PREPEND(links, ctx->links, link);
 184
 185         return 0;
 186
 187 failure:
 188         free(link);
 189         return r;
 190 }
 191
 192 static bool enable_name_policy(void) {
 193         _cleanup_free_ char *line;
 194         char *w, *state;
 195         int r;
 196         size_t l;
 197
 198         r = read_one_line_file("/proc/cmdline", &line);
 199         if (r < 0) {
 200                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
 201                 return true; /* something is very wrong, let's not make it worse */
 202         }
 203
 204         FOREACH_WORD_QUOTED(w, l, line, state)
 205                 if (strneq(w, "net.ifnames=0", l))
 206                         return false;
 207
 208         return true;
 209 }
 210
 211 int link_config_load(link_config_ctx *ctx) {
 212         int r;
 213         char **files, **f;
 214
 215         link_configs_free(ctx);
 216
 217         if (!enable_name_policy()) {
 218                 ctx->enable_name_policy = false;
 219                 log_info("Network interface NamePolicy= disabled on kernel commandline, ignoring.");
 220         }
 221
 222         /* update timestamp */
 223         paths_check_timestamp(ctx->link_dirs, &ctx->link_dirs_ts_usec, true);
 224
 225         r = conf_files_list_strv(&files, ".link", NULL, (const char **)ctx->link_dirs);
 226         if (r < 0) {
 227                 log_error("failed to enumerate link files: %s", strerror(-r));
 228                 return r;
 229         }
 230
 231         STRV_FOREACH_BACKWARDS(f, files) {
 232                 r = load_link(ctx, *f);
 233                 if (r < 0)
 234                         return r;
 235         }
 236
 237         return 0;
 238 }
 239
 240 bool link_config_should_reload(link_config_ctx *ctx) {
 241         return paths_check_timestamp(ctx->link_dirs, &ctx->link_dirs_ts_usec, false);
 242 }
 243
 244 int link_config_get(link_config_ctx *ctx, struct udev_device *device, link_config **ret) {
 245         link_config *link;
 246
 247         LIST_FOREACH(links, link, ctx->links) {
 248
 249                 if (net_match_config(link->match_mac, link->match_path,
 250                                      link->match_driver, link->match_type, NULL,
 251                                      udev_device_get_sysattr_value(device, "address"),
 252                                      udev_device_get_property_value(device, "ID_PATH"),
 253                                      udev_device_get_driver(device),
 254                                      udev_device_get_devtype(device),
 255                                      NULL)) {
 256                         log_debug("Config file %s applies to device %s",
 257                                   link->filename,
 258                                   udev_device_get_sysname(device));
 259                         *ret = link;
 260                         return 0;
 261                 }
 262         }
 263
 264         *ret = NULL;
 265
 266         return -ENOENT;
 267 }
 268
 269 static bool mac_is_random(struct udev_device *device) {
 270         const char *s;
 271         unsigned type;
 272         int r;
 273
 274         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 275         if (!s)
 276                 return false; /* if we don't know, assume it is not random */
 277         r = safe_atou(s, &type);
 278         if (r < 0)
 279                 return false;
 280
 281         /* check for NET_ADDR_RANDOM */
 282         return type == 1;
 283 }
 284
 285 static bool mac_is_permanent(struct udev_device *device) {
 286         const char *s;
 287         unsigned type;
 288         int r;
 289
 290         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 291         if (!s)
 292                 return true; /* if we don't know, assume it is permanent */
 293         r = safe_atou(s, &type);
 294         if (r < 0)
 295                 return true;
 296
 297         /* check for NET_ADDR_PERM */
 298         return type == 0;
 299 }
 300
 301 static int get_mac(struct udev_device *device, bool want_random, struct ether_addr *mac) {
 302         unsigned int seed;
 303         int r, i;
 304
 305         if (want_random)
 306                 seed = random_u();
 307         else {
 308                 const char *name;
 309                 sd_id128_t machine;
 310                 char machineid_buf[33];
 311                 const char *seed_str;
 312
 313                 /* fetch some persistent data unique (on this machine) to this device */
 314                 name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 315                 if (!name) {
 316                         name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 317                         if (!name) {
 318                                 name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 319                                 if (!name)
 320                                         return -ENOENT;
 321                         }
 322                 }
 323                 /* fetch some persistent data unique to this machine */
 324                 r = sd_id128_get_machine(&machine);
 325                 if (r < 0)
 326                         return r;
 327
 328                 /* combine the data */
 329                 seed_str = strappenda(name, sd_id128_to_string(machine, machineid_buf));
 330
 331                 /* hash to get seed */
 332                 seed = string_hash_func(seed_str);
 333         }
 334
 335         srandom(seed);
 336
 337         for(i = 0; i < ETH_ALEN; i++) {
 338                 mac->ether_addr_octet[i] = random();
 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, struct udev_device *device, const char **name) {
 349         const char *old_name;
 350         const char *new_name = NULL;
 351         struct ether_addr generated_mac;
 352         struct ether_addr *mac = NULL;
 353         int r, ifindex;
 354
 355         assert(ctx);
 356         assert(config);
 357         assert(device);
 358         assert(name);
 359
 360         r = link_config_ctx_connect(ctx);
 361         if (r < 0)
 362                 return r;
 363
 364         old_name = udev_device_get_sysname(device);
 365         if (!old_name)
 366                 return -EINVAL;
 367
 368         if (config->description) {
 369                 r = udev_device_set_sysattr_value(device, "ifalias",
 370                                                   config->description);
 371                 if (r < 0)
 372                         log_warning("Could not set description of %s to '%s': %s",
 373                                     old_name, config->description, strerror(-r));
 374         }
 375
 376         r = ethtool_set_speed(ctx->ethtool_fd, old_name, config->speed, config->duplex);
 377         if (r < 0)
 378                 log_warning("Could not set speed or duplex of %s to %u Mbytes (%s): %s",
 379                              old_name, config->speed, duplex_to_string(config->duplex), strerror(-r));
 380
 381         r = ethtool_set_wol(ctx->ethtool_fd, old_name, config->wol);
 382         if (r < 0)
 383                 log_warning("Could not set WakeOnLan of %s to %s: %s",
 384                             old_name, wol_to_string(config->wol), strerror(-r));
 385
 386         ifindex = udev_device_get_ifindex(device);
 387         if (ifindex <= 0) {
 388                 log_warning("Could not find ifindex");
 389                 return -ENODEV;
 390         }
 391
 392         if (ctx->enable_name_policy && config->name_policy) {
 393                 NamePolicy *policy;
 394
 395                 for (policy = config->name_policy; !new_name && *policy != _NAMEPOLICY_INVALID; policy++) {
 396                         switch (*policy) {
 397                                 case NAMEPOLICY_ONBOARD:
 398                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 399                                         break;
 400                                 case NAMEPOLICY_SLOT:
 401                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 402                                         break;
 403                                 case NAMEPOLICY_PATH:
 404                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 405                                         break;
 406                                 case NAMEPOLICY_MAC:
 407                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");
 408                                         break;
 409                                 default:
 410                                         break;
 411                         }
 412                 }
 413         }
 414
 415         if (new_name)
 416                 *name = new_name; /* a name was set by a policy */
 417         else if (config->name)
 418                 *name = config->name; /* a name was set manually in the config */
 419         else
 420                 *name = NULL;
 421
 422         switch (config->mac_policy) {
 423                 case MACPOLICY_PERSISTENT:
 424                         if (!mac_is_permanent(device)) {
 425                                 r = get_mac(device, false, &generated_mac);
 426                                 if (r < 0)
 427                                         return r;
 428                                 mac = &generated_mac;
 429                         }
 430                         break;
 431                 case MACPOLICY_RANDOM:
 432                         if (!mac_is_random(device)) {
 433                                 r = get_mac(device, true, &generated_mac);
 434                                 if (r < 0)
 435                                         return r;
 436                                 mac = &generated_mac;
 437                         }
 438                         break;
 439                 default:
 440                         mac = config->mac;
 441         }
 442
 443         r = rtnl_set_link_properties(ctx->rtnl, ifindex, mac, config->mtu);
 444         if (r < 0) {
 445                 log_warning("Could not set MACAddress or MTU on %s: %s", old_name, strerror(-r));
 446                 return r;
 447         }
 448
 449         return 0;
 450 }
 451
 452 static const char* const mac_policy_table[] = {
 453         [MACPOLICY_PERSISTENT] = "persistent",
 454         [MACPOLICY_RANDOM] = "random"
 455 };
 456
 457 DEFINE_STRING_TABLE_LOOKUP(mac_policy, MACPolicy);
 458 DEFINE_CONFIG_PARSE_ENUM(config_parse_mac_policy, mac_policy, MACPolicy, "Failed to parse MAC address policy");
 459
 460 static const char* const name_policy_table[] = {
 461         [NAMEPOLICY_ONBOARD] = "onboard",
 462         [NAMEPOLICY_SLOT] = "slot",
 463         [NAMEPOLICY_PATH] = "path",
 464         [NAMEPOLICY_MAC] = "mac"
 465 };
 466
 467 DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
 468 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy, _NAMEPOLICY_INVALID, "Failed to parse interface name policy");