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 == -1) {
  94                 r = ethtool_connect(&ctx->ethtool_fd);
  95                 if (r < 0)
  96                         return r;
  97         }
  98
  99         if (!ctx->rtnl) {
 100                 r = sd_rtnl_open(&ctx->rtnl, 0);
 101                 if (r < 0)
 102                         return r;
 103         }
 104
 105         return 0;
 106 }
 107
 108 static void link_configs_free(link_config_ctx *ctx) {
 109         link_config *link, *link_next;
 110
 111         if (!ctx)
 112                 return;
 113
 114         LIST_FOREACH_SAFE(links, link, link_next, ctx->links) {
 115                 free(link->filename);
 116                 free(link->match_path);
 117                 free(link->match_driver);
 118                 free(link->match_type);
 119                 free(link->description);
 120                 free(link->alias);
 121
 122                 free(link);
 123         }
 124 }
 125
 126 void link_config_ctx_free(link_config_ctx *ctx) {
 127         if (!ctx)
 128                 return;
 129
 130         if (ctx->ethtool_fd >= 0)
 131                 close_nointr_nofail(ctx->ethtool_fd);
 132
 133         sd_rtnl_unref(ctx->rtnl);
 134
 135         link_configs_free(ctx);
 136
 137         free(ctx);
 138
 139         return;
 140 }
 141
 142 static int load_link(link_config_ctx *ctx, const char *filename) {
 143         link_config *link;
 144         _cleanup_fclose_ FILE *file;
 145         int r;
 146
 147         assert(ctx);
 148         assert(filename);
 149
 150         file = fopen(filename, "re");
 151         if (!file) {
 152                 if (errno == ENOENT)
 153                         return 0;
 154                 else
 155                         return errno;
 156         }
 157
 158         link = new0(link_config, 1);
 159         if (!link) {
 160                 r = log_oom();
 161                 goto failure;
 162         }
 163
 164         link->mac_policy = _MACPOLICY_INVALID;
 165         link->wol = _WOL_INVALID;
 166         link->duplex = _DUP_INVALID;
 167
 168         r = config_parse(NULL, filename, file, "Match\0Link\0Ethernet\0", config_item_perf_lookup,
 169                          (void*) link_config_gperf_lookup, false, false, link);
 170         if (r < 0) {
 171                 log_warning("Could not parse config file %s: %s", filename, strerror(-r));
 172                 goto failure;
 173         } else
 174                 log_debug("Parsed configuration file %s", filename);
 175
 176         link->filename = strdup(filename);
 177
 178         LIST_PREPEND(links, ctx->links, link);
 179
 180         return 0;
 181
 182 failure:
 183         free(link);
 184         return r;
 185 }
 186
 187 static bool enable_name_policy(void) {
 188         _cleanup_free_ char *line;
 189         char *w, *state;
 190         int r;
 191         size_t l;
 192
 193         r = proc_cmdline(&line);
 194         if (r < 0)
 195                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
 196         if (r <= 0)
 197                 return true;
 198
 199         FOREACH_WORD_QUOTED(w, l, line, state)
 200                 if (strneq(w, "net.ifnames=0", l))
 201                         return false;
 202
 203         return true;
 204 }
 205
 206 int link_config_load(link_config_ctx *ctx) {
 207         int r;
 208         char **files, **f;
 209
 210         link_configs_free(ctx);
 211
 212         if (!enable_name_policy()) {
 213                 ctx->enable_name_policy = false;
 214                 log_info("Network interface NamePolicy= disabled on kernel commandline, ignoring.");
 215         }
 216
 217         /* update timestamp */
 218         paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, true);
 219
 220         r = conf_files_list_strv(&files, ".link", NULL, link_dirs);
 221         if (r < 0) {
 222                 log_error("failed to enumerate link files: %s", strerror(-r));
 223                 return r;
 224         }
 225
 226         STRV_FOREACH_BACKWARDS(f, files) {
 227                 r = load_link(ctx, *f);
 228                 if (r < 0)
 229                         return r;
 230         }
 231
 232         return 0;
 233 }
 234
 235 bool link_config_should_reload(link_config_ctx *ctx) {
 236         return paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, false);
 237 }
 238
 239 int link_config_get(link_config_ctx *ctx, struct udev_device *device, link_config **ret) {
 240         link_config *link;
 241
 242         LIST_FOREACH(links, link, ctx->links) {
 243
 244                 if (net_match_config(link->match_mac, link->match_path, link->match_driver,
 245                                      link->match_type, NULL, link->match_host,
 246                                      link->match_virt, link->match_kernel, link->match_arch,
 247                                      udev_device_get_sysattr_value(device, "address"),
 248                                      udev_device_get_property_value(device, "ID_PATH"),
 249                                      udev_device_get_driver(udev_device_get_parent(device)),
 250                                      udev_device_get_property_value(device, "ID_NET_DRIVER"),
 251                                      udev_device_get_devtype(device),
 252                                      NULL)) {
 253                         log_debug("Config file %s applies to device %s",
 254                                   link->filename,
 255                                   udev_device_get_sysname(device));
 256                         *ret = link;
 257                         return 0;
 258                 }
 259         }
 260
 261         *ret = NULL;
 262
 263         return -ENOENT;
 264 }
 265
 266 static bool mac_is_random(struct udev_device *device) {
 267         const char *s;
 268         unsigned type;
 269         int r;
 270
 271         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 272         if (!s)
 273                 return false; /* if we don't know, assume it is not random */
 274         r = safe_atou(s, &type);
 275         if (r < 0)
 276                 return false;
 277
 278         /* check for NET_ADDR_RANDOM */
 279         return type == 1;
 280 }
 281
 282 static bool mac_is_permanent(struct udev_device *device) {
 283         const char *s;
 284         unsigned type;
 285         int r;
 286
 287         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 288         if (!s)
 289                 return true; /* if we don't know, assume it is permanent */
 290         r = safe_atou(s, &type);
 291         if (r < 0)
 292                 return true;
 293
 294         /* check for NET_ADDR_PERM */
 295         return type == 0;
 296 }
 297
 298 #define HASH_KEY SD_ID128_MAKE(d3,1e,48,fa,90,fe,4b,4c,9d,af,d5,d7,a1,b1,2e,8a)
 299
 300 static int get_mac(struct udev_device *device, bool want_random, struct ether_addr *mac) {
 301         int r;
 302
 303         if (want_random)
 304                 random_bytes(mac->ether_addr_octet, ETH_ALEN);
 305         else {
 306                 const char *name;
 307                 uint8_t result[8];
 308                 size_t l, sz;
 309                 uint8_t *v;
 310
 311                 /* fetch some persistent data unique (on this machine) to this device */
 312                 name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 313                 if (!name) {
 314                         name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 315                         if (!name) {
 316                                 name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 317                                 if (!name)
 318                                         return -ENOENT;
 319                         }
 320                 }
 321
 322                 l = strlen(name);
 323                 sz = sizeof(sd_id128_t) + l;
 324                 v = alloca(sz);
 325
 326                 /* fetch some persistent data unique to this machine */
 327                 r = sd_id128_get_machine((sd_id128_t*) v);
 328                 if (r < 0)
 329                         return r;
 330                 memcpy(v + sizeof(sd_id128_t), name, l);
 331
 332                 /* Let's hash the machine ID plus the device name. We
 333                  * use a fixed, but originally randomly created hash
 334                  * key here. */
 335                 siphash24(result, v, sz, HASH_KEY.bytes);
 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, 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         r = ethtool_set_speed(ctx->ethtool_fd, old_name, config->speed / 1024, config->duplex);
 369         if (r < 0)
 370                 log_warning("Could not set speed or duplex of %s to %u Mbps (%s): %s",
 371                             old_name, config->speed / 1024, duplex_to_string(config->duplex),
 372                             strerror(-r));
 373
 374         r = ethtool_set_wol(ctx->ethtool_fd, old_name, config->wol);
 375         if (r < 0)
 376                 log_warning("Could not set WakeOnLan of %s to %s: %s",
 377                             old_name, wol_to_string(config->wol), strerror(-r));
 378
 379         ifindex = udev_device_get_ifindex(device);
 380         if (ifindex <= 0) {
 381                 log_warning("Could not find ifindex");
 382                 return -ENODEV;
 383         }
 384
 385         if (ctx->enable_name_policy && config->name_policy) {
 386                 NamePolicy *policy;
 387
 388                 for (policy = config->name_policy; !new_name && *policy != _NAMEPOLICY_INVALID; policy++) {
 389                         switch (*policy) {
 390                                 case NAMEPOLICY_DATABASE:
 391                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE");
 392                                         break;
 393                                 case NAMEPOLICY_ONBOARD:
 394                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 395                                         break;
 396                                 case NAMEPOLICY_SLOT:
 397                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 398                                         break;
 399                                 case NAMEPOLICY_PATH:
 400                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 401                                         break;
 402                                 case NAMEPOLICY_MAC:
 403                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");
 404                                         break;
 405                                 default:
 406                                         break;
 407                         }
 408                 }
 409         }
 410
 411         if (new_name)
 412                 *name = new_name; /* a name was set by a policy */
 413         else if (config->name)
 414                 *name = config->name; /* a name was set manually in the config */
 415         else
 416                 *name = NULL;
 417
 418         switch (config->mac_policy) {
 419                 case MACPOLICY_PERSISTENT:
 420                         if (!mac_is_permanent(device)) {
 421                                 r = get_mac(device, false, &generated_mac);
 422                                 if (r < 0)
 423                                         return r;
 424                                 mac = &generated_mac;
 425                         }
 426                         break;
 427                 case MACPOLICY_RANDOM:
 428                         if (!mac_is_random(device)) {
 429                                 r = get_mac(device, true, &generated_mac);
 430                                 if (r < 0)
 431                                         return r;
 432                                 mac = &generated_mac;
 433                         }
 434                         break;
 435                 default:
 436                         mac = config->mac;
 437         }
 438
 439         r = rtnl_set_link_properties(ctx->rtnl, ifindex, config->alias, mac, config->mtu);
 440         if (r < 0) {
 441                 log_warning("Could not set Alias, MACAddress or MTU on %s: %s", old_name, strerror(-r));
 442                 return r;
 443         }
 444
 445         return 0;
 446 }
 447
 448 int link_get_driver(link_config_ctx *ctx, struct udev_device *device, char **ret) {
 449         const char *name;
 450         char *driver;
 451         int r;
 452
 453         r = link_config_ctx_connect(ctx);
 454         if (r < 0)
 455                 return r;
 456
 457         name = udev_device_get_sysname(device);
 458         if (!name)
 459                 return -EINVAL;
 460
 461         r = ethtool_get_driver(ctx->ethtool_fd, name, &driver);
 462         if (r < 0)
 463                 return r;
 464
 465         *ret = driver;
 466         return 0;
 467 }
 468
 469 static const char* const mac_policy_table[] = {
 470         [MACPOLICY_PERSISTENT] = "persistent",
 471         [MACPOLICY_RANDOM] = "random"
 472 };
 473
 474 DEFINE_STRING_TABLE_LOOKUP(mac_policy, MACPolicy);
 475 DEFINE_CONFIG_PARSE_ENUM(config_parse_mac_policy, mac_policy, MACPolicy, "Failed to parse MAC address policy");
 476
 477 static const char* const name_policy_table[] = {
 478         [NAMEPOLICY_DATABASE] = "database",
 479         [NAMEPOLICY_ONBOARD] = "onboard",
 480         [NAMEPOLICY_SLOT] = "slot",
 481         [NAMEPOLICY_PATH] = "path",
 482         [NAMEPOLICY_MAC] = "mac"
 483 };
 484
 485 DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
 486 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy, _NAMEPOLICY_INVALID, "Failed to parse interface name policy");