src/network/networkd-manager.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 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 <resolv.h>
  23
  24 #include "path-util.h"
  25 #include "networkd.h"
  26 #include "libudev-private.h"
  27 #include "udev-util.h"
  28 #include "rtnl-util.h"
  29 #include "mkdir.h"
  30 #include "virt.h"
  31
  32 const char* const network_dirs[] = {
  33         "/etc/systemd/network",
  34         "/run/systemd/network",
  35         "/usr/lib/systemd/network",
  36 #ifdef HAVE_SPLIT_USR
  37         "/lib/systemd/network",
  38 #endif
  39         NULL};
  40
  41 static int dispatch_sigterm(sd_event_source *es, const struct signalfd_siginfo *si, void *userdata) {
  42         Manager *m = userdata;
  43
  44         assert(m);
  45
  46         log_received_signal(LOG_INFO, si);
  47
  48         sd_event_exit(m->event, 0);
  49         return 0;
  50 }
  51
  52 static int setup_signals(Manager *m) {
  53         sigset_t mask;
  54         int r;
  55
  56         assert(m);
  57
  58         assert_se(sigemptyset(&mask) == 0);
  59         sigset_add_many(&mask, SIGINT, SIGTERM, -1);
  60         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
  61
  62         r = sd_event_add_signal(m->event, &m->sigterm_event_source, SIGTERM, dispatch_sigterm, m);
  63         if (r < 0)
  64                 return r;
  65
  66         r = sd_event_add_signal(m->event, &m->sigint_event_source, SIGINT, dispatch_sigterm, m);
  67         if (r < 0)
  68                 return r;
  69
  70         return 0;
  71 }
  72
  73 int manager_new(Manager **ret) {
  74         _cleanup_manager_free_ Manager *m = NULL;
  75         int r;
  76
  77         m = new0(Manager, 1);
  78         if (!m)
  79                 return -ENOMEM;
  80
  81         r = sd_event_default(&m->event);
  82         if (r < 0)
  83                 return r;
  84
  85         sd_event_set_watchdog(m->event, true);
  86
  87         r = sd_rtnl_open(&m->rtnl, RTMGRP_LINK | RTMGRP_IPV4_IFADDR);
  88         if (r < 0)
  89                 return r;
  90
  91         r = sd_bus_default_system(&m->bus);
  92         if (r < 0 && r != -ENOENT) /* TODO: drop when we can rely on kdbus */
  93                 return r;
  94
  95         r = setup_signals(m);
  96         if (r < 0)
  97                 return r;
  98
  99         m->udev = udev_new();
 100         if (!m->udev)
 101                 return -ENOMEM;
 102
 103         /* udev does not initialize devices inside containers,
 104          * so we rely on them being already initialized before
 105          * entering the container */
 106         if (detect_container(NULL) > 0) {
 107                 m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "kernel");
 108                 if (!m->udev_monitor)
 109                         return -ENOMEM;
 110         } else {
 111                 m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev");
 112                 if (!m->udev_monitor)
 113                         return -ENOMEM;
 114         }
 115
 116         m->links = hashmap_new(uint64_hash_func, uint64_compare_func);
 117         if (!m->links)
 118                 return -ENOMEM;
 119
 120         m->netdevs = hashmap_new(string_hash_func, string_compare_func);
 121         if (!m->netdevs)
 122                 return -ENOMEM;
 123
 124         LIST_HEAD_INIT(m->networks);
 125
 126         *ret = m;
 127         m = NULL;
 128
 129         return 0;
 130 }
 131
 132 void manager_free(Manager *m) {
 133         Network *network;
 134         NetDev *netdev;
 135         Link *link;
 136
 137         if (!m)
 138                 return;
 139
 140         udev_monitor_unref(m->udev_monitor);
 141         udev_unref(m->udev);
 142         sd_bus_unref(m->bus);
 143         sd_event_source_unref(m->udev_event_source);
 144         sd_event_source_unref(m->sigterm_event_source);
 145         sd_event_source_unref(m->sigint_event_source);
 146         sd_event_unref(m->event);
 147
 148         while ((network = m->networks))
 149                 network_free(network);
 150
 151         while ((link = hashmap_first(m->links)))
 152                 link_free(link);
 153         hashmap_free(m->links);
 154
 155         while ((netdev = hashmap_first(m->netdevs)))
 156                 netdev_free(netdev);
 157         hashmap_free(m->netdevs);
 158
 159         sd_rtnl_unref(m->rtnl);
 160
 161         free(m);
 162 }
 163
 164 int manager_load_config(Manager *m) {
 165         int r;
 166
 167         /* update timestamp */
 168         paths_check_timestamp(network_dirs, &m->network_dirs_ts_usec, true);
 169
 170         r = netdev_load(m);
 171         if (r < 0)
 172                 return r;
 173
 174         r = network_load(m);
 175         if (r < 0)
 176                 return r;
 177
 178         return 0;
 179 }
 180
 181 bool manager_should_reload(Manager *m) {
 182         return paths_check_timestamp(network_dirs, &m->network_dirs_ts_usec, false);
 183 }
 184
 185 static int manager_process_link(Manager *m, struct udev_device *device) {
 186         Link *link = NULL;
 187         int r;
 188
 189         assert(m);
 190         assert(device);
 191
 192         link_get(m, udev_device_get_ifindex(device), &link);
 193
 194         if (streq_ptr(udev_device_get_action(device), "remove")) {
 195                 log_debug("%s: link removed", udev_device_get_sysname(device));
 196
 197                 if (link)
 198                         link_free(link);
 199         } else {
 200                 if (link) {
 201                         log_debug("%s: link already exists, ignoring",
 202                                   link->ifname);
 203                         return 0;
 204                 }
 205
 206                 r = link_add(m, device, &link);
 207                 if (r < 0) {
 208                         log_error("%s: could not handle link: %s",
 209                                   udev_device_get_sysname(device),
 210                                   strerror(-r));
 211                 } else
 212                         log_debug("%s: link (with ifindex %" PRIu64") added",
 213                                   link->ifname, link->ifindex);
 214         }
 215
 216         return 0;
 217 }
 218
 219 int manager_udev_enumerate_links(Manager *m) {
 220         _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
 221         struct udev_list_entry *item = NULL, *first = NULL;
 222         int r;
 223
 224         assert(m);
 225
 226         e = udev_enumerate_new(m->udev);
 227         if (!e)
 228                 return -ENOMEM;
 229
 230         r = udev_enumerate_add_match_subsystem(e, "net");
 231         if (r < 0)
 232                 return r;
 233
 234         /* udev does not initialize devices inside containers,
 235          * so we rely on them being already initialized before
 236          * entering the container */
 237         if (detect_container(NULL) <= 0) {
 238                 r = udev_enumerate_add_match_is_initialized(e);
 239                 if (r < 0)
 240                         return r;
 241         }
 242
 243         r = udev_enumerate_scan_devices(e);
 244         if (r < 0)
 245                 return r;
 246
 247         first = udev_enumerate_get_list_entry(e);
 248         udev_list_entry_foreach(item, first) {
 249                 _cleanup_udev_device_unref_ struct udev_device *d = NULL;
 250                 int k;
 251
 252                 d = udev_device_new_from_syspath(m->udev, udev_list_entry_get_name(item));
 253                 if (!d)
 254                         return -ENOMEM;
 255
 256                 k = manager_process_link(m, d);
 257                 if (k < 0)
 258                         r = k;
 259         }
 260
 261         return r;
 262 }
 263
 264 static int manager_dispatch_link_udev(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
 265         Manager *m = userdata;
 266         struct udev_monitor *monitor = m->udev_monitor;
 267         _cleanup_udev_device_unref_ struct udev_device *device = NULL;
 268
 269         device = udev_monitor_receive_device(monitor);
 270         if (!device)
 271                 return -ENOMEM;
 272
 273         manager_process_link(m, device);
 274         return 0;
 275 }
 276
 277 int manager_udev_listen(Manager *m) {
 278         int r;
 279
 280         r = udev_monitor_filter_add_match_subsystem_devtype(m->udev_monitor, "net", NULL);
 281         if (r < 0) {
 282                 log_error("Could not add udev monitor filter: %s", strerror(-r));
 283                 return r;
 284         }
 285
 286         r = udev_monitor_enable_receiving(m->udev_monitor);
 287         if (r < 0) {
 288                 log_error("Could not enable udev monitor");
 289                 return r;
 290         }
 291
 292         r = sd_event_add_io(m->event,
 293                         &m->udev_event_source,
 294                         udev_monitor_get_fd(m->udev_monitor),
 295                         EPOLLIN, manager_dispatch_link_udev,
 296                         m);
 297         if (r < 0)
 298                 return r;
 299
 300         return 0;
 301 }
 302
 303 static int manager_rtnl_process_link(sd_rtnl *rtnl, sd_rtnl_message *message, void *userdata) {
 304         Manager *m = userdata;
 305         Link *link;
 306         char *name;
 307         int r, ifindex;
 308
 309         assert(rtnl);
 310         assert(message);
 311         assert(m);
 312
 313         r = sd_rtnl_message_link_get_ifindex(message, &ifindex);
 314         if (r < 0 || ifindex <= 0) {
 315                 log_warning("received RTM_NEWLINK message without valid ifindex");
 316                 return 0;
 317         }
 318
 319         r = sd_rtnl_message_read_string(message, IFLA_IFNAME, &name);
 320         if (r < 0)
 321                 log_warning("received RTM_NEWLINK message without valid ifname");
 322         else {
 323                 NetDev *netdev;
 324
 325                 r = netdev_get(m, name, &netdev);
 326                 if (r >= 0)
 327                         netdev_set_ifindex(netdev, message);
 328         }
 329
 330         r = link_get(m, ifindex, &link);
 331         if (r < 0) {
 332                 log_debug("received RTM_NEWLINK message for untracked ifindex %d", ifindex);
 333                 return 0;
 334         }
 335
 336         /* only track the status of links we want to manage */
 337         if (link->network) {
 338                 r = link_update(link, message);
 339                 if (r < 0)
 340                         return 0;
 341         } else
 342                 log_debug("%s: received RTM_NEWLINK message for unmanaged link", link->ifname);
 343
 344         return 1;
 345 }
 346
 347 int manager_rtnl_listen(Manager *m) {
 348         int r;
 349
 350         r = sd_rtnl_attach_event(m->rtnl, m->event, 0);
 351         if (r < 0)
 352                 return r;
 353
 354         r = sd_rtnl_add_match(m->rtnl, RTM_NEWLINK, &manager_rtnl_process_link, m);
 355         if (r < 0)
 356                 return r;
 357
 358         return 0;
 359 }
 360
 361 int manager_bus_listen(Manager *m) {
 362         int r;
 363
 364         assert(m->event);
 365
 366         if (!m->bus) /* TODO: drop when we can rely on kdbus */
 367                 return 0;
 368
 369         r = sd_bus_attach_event(m->bus, m->event, 0);
 370         if (r < 0)
 371                 return r;
 372
 373         return 0;
 374 }
 375
 376 static void append_dns(FILE *f, struct in_addr *dns, unsigned char family, unsigned *count) {
 377         char buf[INET6_ADDRSTRLEN];
 378         const char *address;
 379
 380         address = inet_ntop(family, dns, buf, INET6_ADDRSTRLEN);
 381         if (!address) {
 382                 log_warning("Invalid DNS address. Ignoring.");
 383                 return;
 384         }
 385
 386         if (*count == MAXNS)
 387                 fputs("# Too many DNS servers configured, the following entries "
 388                       "will be ignored\n", f);
 389
 390         fprintf(f, "nameserver %s\n", address);
 391
 392         (*count) ++;
 393 }
 394
 395 int manager_update_resolv_conf(Manager *m) {
 396         _cleanup_free_ char *temp_path = NULL;
 397         _cleanup_fclose_ FILE *f = NULL;
 398         Link *link;
 399         Iterator i;
 400         unsigned count = 0;
 401         const char *domainname = NULL;
 402         int r;
 403
 404         assert(m);
 405
 406         r = fopen_temporary("/run/systemd/network/resolv.conf", &f, &temp_path);
 407         if (r < 0)
 408                 return r;
 409
 410         fchmod(fileno(f), 0644);
 411
 412         fputs("# This file is managed by systemd-networkd(8). Do not edit.\n#\n"
 413               "# Third party programs must not access this file directly, but\n"
 414               "# only through the symlink at /etc/resolv.conf. To manage\n"
 415               "# resolv.conf(5) in a different way, replace the symlink by a\n"
 416               "# static file or a different symlink.\n\n", f);
 417
 418         HASHMAP_FOREACH(link, m->links, i) {
 419                 if (link->dhcp_lease) {
 420                         struct in_addr *nameservers;
 421                         size_t nameservers_size;
 422
 423                         if (link->network->dhcp_dns) {
 424                                 r = sd_dhcp_lease_get_dns(link->dhcp_lease, &nameservers, &nameservers_size);
 425                                 if (r >= 0) {
 426                                         unsigned j;
 427
 428                                         for (j = 0; j < nameservers_size; j++)
 429                                                 append_dns(f, &nameservers[j], AF_INET, &count);
 430                                 }
 431                         }
 432
 433                         if (link->network->dhcp_domainname && !domainname) {
 434                                 r = sd_dhcp_lease_get_domainname(link->dhcp_lease, &domainname);
 435                                 if (r >= 0)
 436                                        fprintf(f, "domain %s\n", domainname);
 437                         }
 438                 }
 439         }
 440
 441         HASHMAP_FOREACH(link, m->links, i) {
 442                 if (link->network && link->network->dns) {
 443                         Address *address;
 444                         Iterator j;
 445
 446                         SET_FOREACH(address, link->network->dns, j) {
 447                                 append_dns(f, &address->in_addr.in,
 448                                            address->family, &count);
 449                         }
 450                 }
 451         }
 452
 453         fflush(f);
 454
 455         if (ferror(f) || rename(temp_path, "/run/systemd/network/resolv.conf") < 0) {
 456                 r = -errno;
 457                 unlink("/run/systemd/network/resolv.conf");
 458                 unlink(temp_path);
 459                 return r;
 460         }
 461
 462         return 0;
 463 }