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         safe_close(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, link->match_driver,
 244                                      link->match_type, NULL, link->match_host,
 245                                      link->match_virt, link->match_kernel, link->match_arch,
 246                                      udev_device_get_sysattr_value(device, "address"),
 247                                      udev_device_get_property_value(device, "ID_PATH"),
 248                                      udev_device_get_driver(udev_device_get_parent(device)),
 249                                      udev_device_get_property_value(device, "ID_NET_DRIVER"),
 250                                      udev_device_get_devtype(device),
 251                                      NULL)) {
 252                         log_debug("Config file %s applies to device %s",
 253                                   link->filename,
 254                                   udev_device_get_sysname(device));
 255                         *ret = link;
 256                         return 0;
 257                 }
 258         }
 259
 260         *ret = NULL;
 261
 262         return -ENOENT;
 263 }
 264
 265 static bool mac_is_random(struct udev_device *device) {
 266         const char *s;
 267         unsigned type;
 268         int r;
 269
 270         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 271         if (!s)
 272                 return false; /* if we don't know, assume it is not random */
 273         r = safe_atou(s, &type);
 274         if (r < 0)
 275                 return false;
 276
 277         /* check for NET_ADDR_RANDOM */
 278         return type == 1;
 279 }
 280
 281 static bool mac_is_permanent(struct udev_device *device) {
 282         const char *s;
 283         unsigned type;
 284         int r;
 285
 286         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 287         if (!s)
 288                 return true; /* if we don't know, assume it is permanent */
 289         r = safe_atou(s, &type);
 290         if (r < 0)
 291                 return true;
 292
 293         /* check for NET_ADDR_PERM */
 294         return type == 0;
 295 }
 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                 uint8_t result[8];
 304
 305                 r = net_get_unique_predictable_data(device, result);
 306                 if (r < 0)
 307                         return r;
 308
 309                 assert_cc(ETH_ALEN <= sizeof(result));
 310                 memcpy(mac->ether_addr_octet, result, ETH_ALEN);
 311         }
 312
 313         /* see eth_random_addr in the kernel */
 314         mac->ether_addr_octet[0] &= 0xfe;        /* clear multicast bit */
 315         mac->ether_addr_octet[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 316
 317         return 0;
 318 }
 319
 320 int link_config_apply(link_config_ctx *ctx, link_config *config, struct udev_device *device, const char **name) {
 321         const char *old_name;
 322         const char *new_name = NULL;
 323         struct ether_addr generated_mac;
 324         struct ether_addr *mac = NULL;
 325         int r, ifindex;
 326
 327         assert(ctx);
 328         assert(config);
 329         assert(device);
 330         assert(name);
 331
 332         r = link_config_ctx_connect(ctx);
 333         if (r < 0)
 334                 return r;
 335
 336         old_name = udev_device_get_sysname(device);
 337         if (!old_name)
 338                 return -EINVAL;
 339
 340         r = ethtool_set_speed(ctx->ethtool_fd, old_name, config->speed / 1024, config->duplex);
 341         if (r < 0)
 342                 log_warning("Could not set speed or duplex of %s to %u Mbps (%s): %s",
 343                             old_name, config->speed / 1024, duplex_to_string(config->duplex),
 344                             strerror(-r));
 345
 346         r = ethtool_set_wol(ctx->ethtool_fd, old_name, config->wol);
 347         if (r < 0)
 348                 log_warning("Could not set WakeOnLan of %s to %s: %s",
 349                             old_name, wol_to_string(config->wol), strerror(-r));
 350
 351         ifindex = udev_device_get_ifindex(device);
 352         if (ifindex <= 0) {
 353                 log_warning("Could not find ifindex");
 354                 return -ENODEV;
 355         }
 356
 357         if (ctx->enable_name_policy && config->name_policy) {
 358                 NamePolicy *policy;
 359
 360                 for (policy = config->name_policy; !new_name && *policy != _NAMEPOLICY_INVALID; policy++) {
 361                         switch (*policy) {
 362                                 case NAMEPOLICY_DATABASE:
 363                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE");
 364                                         break;
 365                                 case NAMEPOLICY_ONBOARD:
 366                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 367                                         break;
 368                                 case NAMEPOLICY_SLOT:
 369                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 370                                         break;
 371                                 case NAMEPOLICY_PATH:
 372                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 373                                         break;
 374                                 case NAMEPOLICY_MAC:
 375                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");
 376                                         break;
 377                                 default:
 378                                         break;
 379                         }
 380                 }
 381         }
 382
 383         if (new_name)
 384                 *name = new_name; /* a name was set by a policy */
 385         else if (config->name)
 386                 *name = config->name; /* a name was set manually in the config */
 387         else
 388                 *name = NULL;
 389
 390         switch (config->mac_policy) {
 391                 case MACPOLICY_PERSISTENT:
 392                         if (!mac_is_permanent(device)) {
 393                                 r = get_mac(device, false, &generated_mac);
 394                                 if (r < 0)
 395                                         return r;
 396                                 mac = &generated_mac;
 397                         }
 398                         break;
 399                 case MACPOLICY_RANDOM:
 400                         if (!mac_is_random(device)) {
 401                                 r = get_mac(device, true, &generated_mac);
 402                                 if (r < 0)
 403                                         return r;
 404                                 mac = &generated_mac;
 405                         }
 406                         break;
 407                 default:
 408                         mac = config->mac;
 409         }
 410
 411         r = rtnl_set_link_properties(ctx->rtnl, ifindex, config->alias, mac, config->mtu);
 412         if (r < 0) {
 413                 log_warning("Could not set Alias, MACAddress or MTU on %s: %s", old_name, strerror(-r));
 414                 return r;
 415         }
 416
 417         return 0;
 418 }
 419
 420 int link_get_driver(link_config_ctx *ctx, struct udev_device *device, char **ret) {
 421         const char *name;
 422         char *driver;
 423         int r;
 424
 425         r = link_config_ctx_connect(ctx);
 426         if (r < 0)
 427                 return r;
 428
 429         name = udev_device_get_sysname(device);
 430         if (!name)
 431                 return -EINVAL;
 432
 433         r = ethtool_get_driver(ctx->ethtool_fd, name, &driver);
 434         if (r < 0)
 435                 return r;
 436
 437         *ret = driver;
 438         return 0;
 439 }
 440
 441 static const char* const mac_policy_table[_MACPOLICY_MAX] = {
 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[_NAMEPOLICY_MAX] = {
 450         [NAMEPOLICY_DATABASE] = "database",
 451         [NAMEPOLICY_ONBOARD] = "onboard",
 452         [NAMEPOLICY_SLOT] = "slot",
 453         [NAMEPOLICY_PATH] = "path",
 454         [NAMEPOLICY_MAC] = "mac"
 455 };
 456
 457 DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
 458 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy, _NAMEPOLICY_INVALID, "Failed to parse interface name policy");