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 #include "siphash24.h"
  43
  44 struct link_config_ctx {
  45         LIST_HEAD(link_config, links);
  46
  47         int ethtool_fd;
  48
  49         bool enable_name_policy;
  50
  51         sd_rtnl *rtnl;
  52
  53         usec_t link_dirs_ts_usec;
  54 };
  55
  56 static const char* const link_dirs[] = {
  57         "/etc/systemd/network",
  58         "/run/systemd/network",
  59         "/usr/lib/systemd/network",
  60 #ifdef HAVE_SPLIT_USR
  61         "/lib/systemd/network",
  62 #endif
  63         NULL};
  64
  65 DEFINE_TRIVIAL_CLEANUP_FUNC(link_config_ctx*, link_config_ctx_free);
  66 #define _cleanup_link_config_ctx_free_ _cleanup_(link_config_ctx_freep)
  67
  68 int link_config_ctx_new(link_config_ctx **ret) {
  69         _cleanup_link_config_ctx_free_ link_config_ctx *ctx = NULL;
  70
  71         if (!ret)
  72                 return -EINVAL;
  73
  74         ctx = new0(link_config_ctx, 1);
  75         if (!ctx)
  76                 return -ENOMEM;
  77
  78         LIST_HEAD_INIT(ctx->links);
  79
  80         ctx->ethtool_fd = -1;
  81
  82         ctx->enable_name_policy = true;
  83
  84         *ret = ctx;
  85         ctx = NULL;
  86
  87         return 0;
  88 }
  89
  90 static int link_config_ctx_connect(link_config_ctx *ctx) {
  91         int r;
  92
  93         if (ctx->ethtool_fd >= 0 && ctx->rtnl)
  94                 return 0;
  95
  96         r = ethtool_connect(&ctx->ethtool_fd);
  97         if (r < 0)
  98                 return r;
  99
 100         r = sd_rtnl_open(0, &ctx->rtnl);
 101         if (r < 0)
 102                 return r;
 103
 104         return 0;
 105 }
 106
 107 static void link_configs_free(link_config_ctx *ctx) {
 108         link_config *link, *link_next;
 109
 110         if (!ctx)
 111                 return;
 112
 113         LIST_FOREACH_SAFE(links, link, link_next, ctx->links) {
 114                 free(link->filename);
 115                 free(link->match_path);
 116                 free(link->match_driver);
 117                 free(link->match_type);
 118                 free(link->description);
 119                 free(link->alias);
 120
 121                 free(link);
 122         }
 123 }
 124
 125 void link_config_ctx_free(link_config_ctx *ctx) {
 126         if (!ctx)
 127                 return;
 128
 129         if (ctx->ethtool_fd >= 0)
 130                 close_nointr_nofail(ctx->ethtool_fd);
 131
 132         sd_rtnl_unref(ctx->rtnl);
 133
 134         link_configs_free(ctx);
 135
 136         free(ctx);
 137
 138         return;
 139 }
 140
 141 static int load_link(link_config_ctx *ctx, const char *filename) {
 142         link_config *link;
 143         _cleanup_fclose_ FILE *file;
 144         int r;
 145
 146         assert(ctx);
 147         assert(filename);
 148
 149         file = fopen(filename, "re");
 150         if (!file) {
 151                 if (errno == ENOENT)
 152                         return 0;
 153                 else
 154                         return errno;
 155         }
 156
 157         link = new0(link_config, 1);
 158         if (!link) {
 159                 r = log_oom();
 160                 goto failure;
 161         }
 162
 163         link->mac_policy = _MACPOLICY_INVALID;
 164         link->wol = _WOL_INVALID;
 165         link->duplex = _DUP_INVALID;
 166
 167         r = config_parse(NULL, filename, file, "Match\0Link\0Ethernet\0", config_item_perf_lookup,
 168                          (void*) link_config_gperf_lookup, false, false, link);
 169         if (r < 0) {
 170                 log_warning("Could not parse config file %s: %s", filename, strerror(-r));
 171                 goto failure;
 172         } else
 173                 log_debug("Parsed configuration file %s", filename);
 174
 175         link->filename = strdup(filename);
 176
 177         LIST_PREPEND(links, ctx->links, link);
 178
 179         return 0;
 180
 181 failure:
 182         free(link);
 183         return r;
 184 }
 185
 186 static bool enable_name_policy(void) {
 187         _cleanup_free_ char *line;
 188         char *w, *state;
 189         int r;
 190         size_t l;
 191
 192         r = proc_cmdline(&line);
 193         if (r < 0)
 194                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
 195         if (r <= 0)
 196                 return true;
 197
 198         FOREACH_WORD_QUOTED(w, l, line, state)
 199                 if (strneq(w, "net.ifnames=0", l))
 200                         return false;
 201
 202         return true;
 203 }
 204
 205 int link_config_load(link_config_ctx *ctx) {
 206         int r;
 207         char **files, **f;
 208
 209         link_configs_free(ctx);
 210
 211         if (!enable_name_policy()) {
 212                 ctx->enable_name_policy = false;
 213                 log_info("Network interface NamePolicy= disabled on kernel commandline, ignoring.");
 214         }
 215
 216         /* update timestamp */
 217         paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, true);
 218
 219         r = conf_files_list_strv(&files, ".link", NULL, link_dirs);
 220         if (r < 0) {
 221                 log_error("failed to enumerate link files: %s", strerror(-r));
 222                 return r;
 223         }
 224
 225         STRV_FOREACH_BACKWARDS(f, files) {
 226                 r = load_link(ctx, *f);
 227                 if (r < 0)
 228                         return r;
 229         }
 230
 231         return 0;
 232 }
 233
 234 bool link_config_should_reload(link_config_ctx *ctx) {
 235         return paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, false);
 236 }
 237
 238 int link_config_get(link_config_ctx *ctx, struct udev_device *device, link_config **ret) {
 239         link_config *link;
 240
 241         LIST_FOREACH(links, link, ctx->links) {
 242
 243                 if (net_match_config(link->match_mac, link->match_path,
 244                                      link->match_driver, link->match_type, NULL,
 245                                      udev_device_get_sysattr_value(device, "address"),
 246                                      udev_device_get_property_value(device, "ID_PATH"),
 247                                      udev_device_get_driver(udev_device_get_parent(device)),
 248                                      udev_device_get_devtype(device),
 249                                      NULL)) {
 250                         log_debug("Config file %s applies to device %s",
 251                                   link->filename,
 252                                   udev_device_get_sysname(device));
 253                         *ret = link;
 254                         return 0;
 255                 }
 256         }
 257
 258         *ret = NULL;
 259
 260         return -ENOENT;
 261 }
 262
 263 static bool mac_is_random(struct udev_device *device) {
 264         const char *s;
 265         unsigned type;
 266         int r;
 267
 268         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 269         if (!s)
 270                 return false; /* if we don't know, assume it is not random */
 271         r = safe_atou(s, &type);
 272         if (r < 0)
 273                 return false;
 274
 275         /* check for NET_ADDR_RANDOM */
 276         return type == 1;
 277 }
 278
 279 static bool mac_is_permanent(struct udev_device *device) {
 280         const char *s;
 281         unsigned type;
 282         int r;
 283
 284         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 285         if (!s)
 286                 return true; /* if we don't know, assume it is permanent */
 287         r = safe_atou(s, &type);
 288         if (r < 0)
 289                 return true;
 290
 291         /* check for NET_ADDR_PERM */
 292         return type == 0;
 293 }
 294
 295 #define HASH_KEY SD_ID128_MAKE(d3,1e,48,fa,90,fe,4b,4c,9d,af,d5,d7,a1,b1,2e,8a)
 296
 297 static int get_mac(struct udev_device *device, bool want_random, struct ether_addr *mac) {
 298         int r;
 299
 300         if (want_random)
 301                 random_bytes(mac->ether_addr_octet, ETH_ALEN);
 302         else {
 303                 const char *name;
 304                 uint8_t result[8];
 305                 size_t l, sz;
 306                 uint8_t *v;
 307
 308                 /* fetch some persistent data unique (on this machine) to this device */
 309                 name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 310                 if (!name) {
 311                         name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 312                         if (!name) {
 313                                 name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 314                                 if (!name)
 315                                         return -ENOENT;
 316                         }
 317                 }
 318
 319                 l = strlen(name);
 320                 sz = sizeof(sd_id128_t) + l;
 321                 v = alloca(sz);
 322
 323                 /* fetch some persistent data unique to this machine */
 324                 r = sd_id128_get_machine((sd_id128_t*) v);
 325                 if (r < 0)
 326                         return r;
 327                 memcpy(v + sizeof(sd_id128_t), name, l);
 328
 329                 /* Let's hash the machine ID plus the device name. We
 330                  * use a fixed, but originally randomly created hash
 331                  * key here. */
 332                 siphash24(result, v, sz, HASH_KEY.bytes);
 333
 334                 assert_cc(ETH_ALEN <= sizeof(result));
 335                 memcpy(mac->ether_addr_octet, result, ETH_ALEN);
 336         }
 337
 338         /* see eth_random_addr in the kernel */
 339         mac->ether_addr_octet[0] &= 0xfe;        /* clear multicast bit */
 340         mac->ether_addr_octet[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 341
 342         return 0;
 343 }
 344
 345 int link_config_apply(link_config_ctx *ctx, link_config *config, struct udev_device *device, const char **name) {
 346         const char *old_name;
 347         const char *new_name = NULL;
 348         struct ether_addr generated_mac;
 349         struct ether_addr *mac = NULL;
 350         int r, ifindex;
 351
 352         assert(ctx);
 353         assert(config);
 354         assert(device);
 355         assert(name);
 356
 357         r = link_config_ctx_connect(ctx);
 358         if (r < 0)
 359                 return r;
 360
 361         old_name = udev_device_get_sysname(device);
 362         if (!old_name)
 363                 return -EINVAL;
 364
 365         r = ethtool_set_speed(ctx->ethtool_fd, old_name, config->speed, config->duplex);
 366         if (r < 0)
 367                 log_warning("Could not set speed or duplex of %s to %u Mbytes (%s): %s",
 368                              old_name, config->speed, duplex_to_string(config->duplex), strerror(-r));
 369
 370         r = ethtool_set_wol(ctx->ethtool_fd, old_name, config->wol);
 371         if (r < 0)
 372                 log_warning("Could not set WakeOnLan of %s to %s: %s",
 373                             old_name, wol_to_string(config->wol), strerror(-r));
 374
 375         ifindex = udev_device_get_ifindex(device);
 376         if (ifindex <= 0) {
 377                 log_warning("Could not find ifindex");
 378                 return -ENODEV;
 379         }
 380
 381         if (ctx->enable_name_policy && config->name_policy) {
 382                 NamePolicy *policy;
 383
 384                 for (policy = config->name_policy; !new_name && *policy != _NAMEPOLICY_INVALID; policy++) {
 385                         switch (*policy) {
 386                                 case NAMEPOLICY_ONBOARD:
 387                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 388                                         break;
 389                                 case NAMEPOLICY_SLOT:
 390                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 391                                         break;
 392                                 case NAMEPOLICY_PATH:
 393                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 394                                         break;
 395                                 case NAMEPOLICY_MAC:
 396                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");
 397                                         break;
 398                                 default:
 399                                         break;
 400                         }
 401                 }
 402         }
 403
 404         if (new_name)
 405                 *name = new_name; /* a name was set by a policy */
 406         else if (config->name)
 407                 *name = config->name; /* a name was set manually in the config */
 408         else
 409                 *name = NULL;
 410
 411         switch (config->mac_policy) {
 412                 case MACPOLICY_PERSISTENT:
 413                         if (!mac_is_permanent(device)) {
 414                                 r = get_mac(device, false, &generated_mac);
 415                                 if (r < 0)
 416                                         return r;
 417                                 mac = &generated_mac;
 418                         }
 419                         break;
 420                 case MACPOLICY_RANDOM:
 421                         if (!mac_is_random(device)) {
 422                                 r = get_mac(device, true, &generated_mac);
 423                                 if (r < 0)
 424                                         return r;
 425                                 mac = &generated_mac;
 426                         }
 427                         break;
 428                 default:
 429                         mac = config->mac;
 430         }
 431
 432         r = rtnl_set_link_properties(ctx->rtnl, ifindex, config->alias, mac, config->mtu);
 433         if (r < 0) {
 434                 log_warning("Could not set Alias, MACAddress or MTU on %s: %s", old_name, strerror(-r));
 435                 return r;
 436         }
 437
 438         return 0;
 439 }
 440
 441 static const char* const mac_policy_table[] = {
 442         [MACPOLICY_PERSISTENT] = "persistent",
 443         [MACPOLICY_RANDOM] = "random"
 444 };
 445
 446 DEFINE_STRING_TABLE_LOOKUP(mac_policy, MACPolicy);
 447 DEFINE_CONFIG_PARSE_ENUM(config_parse_mac_policy, mac_policy, MACPolicy, "Failed to parse MAC address policy");
 448
 449 static const char* const name_policy_table[] = {
 450         [NAMEPOLICY_ONBOARD] = "onboard",
 451         [NAMEPOLICY_SLOT] = "slot",
 452         [NAMEPOLICY_PATH] = "path",
 453         [NAMEPOLICY_MAC] = "mac"
 454 };
 455
 456 DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
 457 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy, _NAMEPOLICY_INVALID, "Failed to parse interface name policy");