git.ozlabs.org Git - petitboot/blob - discover/network.c

   1
   2 #include <stdbool.h>
   3 #include <stdint.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <errno.h>
   7 #include <sys/socket.h>
   8 #include <linux/if.h>
   9 #include <linux/netlink.h>
  10 #include <linux/rtnetlink.h>
  11 #include <i18n/i18n.h>
  12
  13 #include <log/log.h>
  14 #include <list/list.h>
  15 #include <file/file.h>
  16 #include <types/types.h>
  17 #include <talloc/talloc.h>
  18 #include <waiter/waiter.h>
  19 #include <process/process.h>
  20 #include <system/system.h>
  21
  22 #include "network.h"
  23 #include "sysinfo.h"
  24 #include "platform.h"
  25 #include "device-handler.h"
  26 #include "paths.h"
  27
  28 #define HWADDR_SIZE     6
  29 #define PIDFILE_BASE    (LOCAL_STATE_DIR "/petitboot/")
  30 #define INITIAL_BUFSIZE 4096
  31
  32 #define for_each_nlmsg(buf, nlmsg, len) \
  33         for (nlmsg = (struct nlmsghdr *)buf; \
  34                 NLMSG_OK(nlmsg, len) && nlmsg->nlmsg_type != NLMSG_DONE; \
  35                 nlmsg = NLMSG_NEXT(nlmsg, len))
  36
  37 #define for_each_rta(buf, rta, attrlen) \
  38         for (rta = (struct rtattr *)(buf); RTA_OK(rta, attrlen); \
  39                         rta = RTA_NEXT(rta, attrlen))
  40
  41
  42 struct interface {
  43         int     ifindex;
  44         char    name[IFNAMSIZ];
  45         uint8_t hwaddr[HWADDR_SIZE];
  46
  47         enum {
  48                 IFSTATE_NEW,
  49                 IFSTATE_UP_WAITING_LINK,
  50                 IFSTATE_CONFIGURED,
  51                 IFSTATE_IGNORED,
  52         } state;
  53
  54         struct list_item list;
  55         struct process *udhcpc_process;
  56         struct discover_device *dev;
  57         bool ready;
  58 };
  59
  60 struct network {
  61         struct list             interfaces;
  62         struct device_handler   *handler;
  63         struct waiter           *waiter;
  64         int                     netlink_sd;
  65         void                    *netlink_buf;
  66         unsigned int            netlink_buf_size;
  67         bool                    manual_config;
  68         bool                    dry_run;
  69 };
  70
  71 static char *mac_bytes_to_string(void *ctx, uint8_t *addr, int len)
  72 {
  73         const int l = strlen("xx:");
  74         char *buf;
  75         int i;
  76
  77         if (len <= 0)
  78                 return talloc_strdup(ctx, "");
  79
  80         buf = talloc_array(ctx, char, (len * l) + 1);
  81
  82         for (i = 0; i < len; i++)
  83                 sprintf(buf + (l * i), "%02x:", addr[i]);
  84
  85         *(buf + (l * len) - 1) = '\0';
  86
  87         return buf;
  88 }
  89
  90 static const struct interface_config *find_config_by_hwaddr(
  91                 uint8_t *hwaddr)
  92 {
  93         const struct config *config;
  94         unsigned int i;
  95
  96         config = config_get();
  97         if (!config)
  98                 return NULL;
  99
 100         for (i = 0; i < config->network.n_interfaces; i++) {
 101                 struct interface_config *ifconf = config->network.interfaces[i];
 102
 103                 if (!memcmp(ifconf->hwaddr, hwaddr, HWADDR_SIZE))
 104                         return ifconf;
 105         }
 106
 107         return NULL;
 108 }
 109
 110 static struct interface *find_interface_by_ifindex(struct network *network,
 111                 int ifindex)
 112 {
 113         struct interface *interface;
 114
 115         list_for_each_entry(&network->interfaces, interface, list)
 116                 if (interface->ifindex == ifindex)
 117                         return interface;
 118
 119         return NULL;
 120 }
 121
 122 static struct interface *find_interface_by_name(struct network *network,
 123                 const char *name)
 124 {
 125         struct interface *interface;
 126
 127         list_for_each_entry(&network->interfaces, interface, list)
 128                 if (!strcmp(interface->name, name))
 129                         return interface;
 130
 131         return NULL;
 132 }
 133
 134 static struct interface *find_interface_by_uuid(struct network *network,
 135                 const char *uuid)
 136 {
 137         struct interface *interface;
 138         char *mac;
 139
 140         list_for_each_entry(&network->interfaces, interface, list) {
 141                 mac = mac_bytes_to_string(interface, interface->hwaddr,
 142                                         sizeof(interface->hwaddr));
 143                 if (!strcmp(mac, uuid)) {
 144                         talloc_free(mac);
 145                         return interface;
 146                 }
 147                 talloc_free(mac);
 148         }
 149
 150         return NULL;
 151 }
 152
 153 uint8_t *find_mac_by_name(void *ctx, struct network *network,
 154                 const char *name)
 155 {
 156         struct interface *interface;
 157
 158         interface = find_interface_by_name(network, name);
 159         if (!interface)
 160                 return NULL;
 161
 162         return talloc_memdup(ctx, &interface->hwaddr,
 163                              sizeof(uint8_t) * HWADDR_SIZE);
 164 }
 165
 166 static int network_init_netlink(struct network *network)
 167 {
 168         struct sockaddr_nl addr;
 169         int rc;
 170
 171         memset(&addr, 0, sizeof(addr));
 172         addr.nl_family = AF_NETLINK;
 173         addr.nl_groups = RTMGRP_LINK;
 174
 175         network->netlink_sd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
 176         if (network->netlink_sd < 0) {
 177                 perror("socket(AF_NETLINK)");
 178                 return -1;
 179         }
 180
 181         rc = bind(network->netlink_sd, (struct sockaddr *)&addr, sizeof(addr));
 182         if (rc) {
 183                 perror("bind(sockaddr_nl)");
 184                 close(network->netlink_sd);
 185                 return -1;
 186         }
 187
 188         network->netlink_buf_size = INITIAL_BUFSIZE;
 189         network->netlink_buf = talloc_array(network, char,
 190                                 network->netlink_buf_size);
 191
 192         return 0;
 193 }
 194
 195 static int network_send_link_query(struct network *network)
 196 {
 197         int rc;
 198         struct {
 199                 struct nlmsghdr nlmsg;
 200                 struct rtgenmsg rtmsg;
 201         } msg;
 202
 203         memset(&msg, 0, sizeof(msg));
 204
 205         msg.nlmsg.nlmsg_len = sizeof(msg);
 206         msg.nlmsg.nlmsg_type = RTM_GETLINK;
 207         msg.nlmsg.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT;
 208         msg.nlmsg.nlmsg_seq = 0;
 209         msg.nlmsg.nlmsg_pid = 0;
 210         msg.rtmsg.rtgen_family = AF_UNSPEC;
 211
 212         rc = send(network->netlink_sd, &msg, sizeof(msg), MSG_NOSIGNAL);
 213         if (rc != sizeof(msg))
 214                 return -1;
 215
 216         return 0;
 217 }
 218
 219 static void create_interface_dev(struct network *network,
 220                 struct interface *interface)
 221 {
 222         char *uuid = mac_bytes_to_string(interface, interface->hwaddr,
 223                                                 sizeof(interface->hwaddr));
 224
 225         interface->dev = discover_device_create(network->handler, uuid,
 226                                                 interface->name);
 227         interface->dev->device->type = DEVICE_TYPE_NETWORK;
 228         device_handler_add_device(network->handler, interface->dev);
 229         talloc_free(uuid);
 230 }
 231
 232 static void remove_interface(struct network *network,
 233                 struct interface *interface)
 234 {
 235         if (interface->dev)
 236                 device_handler_remove(network->handler, interface->dev);
 237         list_remove(&interface->list);
 238         talloc_free(interface);
 239 }
 240
 241 void network_register_device(struct network *network,
 242                 struct discover_device *dev)
 243 {
 244         struct interface *iface;
 245
 246         if (dev->uuid)
 247                 iface = find_interface_by_uuid(network, dev->uuid);
 248         else
 249                 iface = find_interface_by_name(network, dev->label);
 250         if (!iface)
 251                 return;
 252
 253         iface->dev = dev;
 254         dev->uuid = mac_bytes_to_string(iface->dev, iface->hwaddr,
 255                         sizeof(iface->hwaddr));
 256 }
 257
 258 void network_unregister_device(struct network *network,
 259                 struct discover_device *dev)
 260 {
 261         struct interface *iface;
 262
 263         iface = find_interface_by_uuid(network, dev->uuid);
 264         if (!iface)
 265                 return;
 266
 267         iface->dev = NULL;
 268 }
 269
 270 static int interface_change(struct interface *interface, bool up)
 271 {
 272         const char *statestr = up ? "up" : "down";
 273         int rc;
 274
 275         if (!up && interface->udhcpc_process) {
 276                 /* we don't care about the callback from here */
 277                 interface->udhcpc_process->exit_cb = NULL;
 278                 interface->udhcpc_process->data = NULL;
 279                 process_stop_async(interface->udhcpc_process);
 280                 process_release(interface->udhcpc_process);
 281         }
 282
 283         if (!up) {
 284                 rc = process_run_simple(interface, pb_system_apps.ip,
 285                                 "address", "flush", "dev", interface->name,
 286                                 NULL);
 287                 if (rc)
 288                         pb_log("failed to flush addresses from interface %s\n",
 289                                 interface->name);
 290         }
 291
 292         rc = process_run_simple(interface, pb_system_apps.ip,
 293                         "link", "set", interface->name, statestr, NULL);
 294         if (rc) {
 295                 pb_log("failed to bring interface %s %s\n", interface->name,
 296                                 statestr);
 297                 return -1;
 298         }
 299         return 0;
 300 }
 301
 302 static int interface_up(struct interface *interface)
 303 {
 304         return interface_change(interface, true);
 305 }
 306
 307 static int interface_down(struct interface *interface)
 308 {
 309         return interface_change(interface, false);
 310 }
 311
 312 static void udhcpc_process_exit(struct process *process)
 313 {
 314         struct interface *interface = process->data;
 315         pb_debug("udhcp client [pid %d] for interface %s exited, rc %d\n",
 316                         process->pid, interface->name, process->exit_status);
 317         interface->udhcpc_process = NULL;
 318         process_release(process);
 319 }
 320
 321 static void configure_interface_dhcp(struct network *network,
 322                 struct interface *interface)
 323 {
 324         const struct platform *platform;
 325         char pidfile[256], id[10];
 326         struct process *process;
 327         int rc;
 328         const char *argv[] = {
 329                 pb_system_apps.udhcpc,
 330                 "-R",
 331                 "-f",
 332                 "-O", "pxeconffile",
 333                 "-O", "pxepathprefix",
 334                 "-p", pidfile,
 335                 "-i", interface->name,
 336                 "-x", id, /* [11,12] - dhcp client identifier */
 337                 NULL,
 338         };
 339
 340         device_handler_status_dev_info(network->handler, interface->dev,
 341                         _("Configuring with DHCP"));
 342
 343         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
 344                         PIDFILE_BASE, interface->name);
 345
 346         platform = platform_get();
 347         if (platform && platform->dhcp_arch_id != 0xffff)
 348                 snprintf(id, sizeof(id), "0x5d:%04x", platform->dhcp_arch_id);
 349         else
 350                 argv[11] = NULL;
 351
 352         process = process_create(interface);
 353
 354         process->path = pb_system_apps.udhcpc;
 355         process->argv = argv;
 356         process->exit_cb = udhcpc_process_exit;
 357         process->data = interface;
 358
 359         rc = process_run_async(process);
 360
 361         if (rc)
 362                 process_release(process);
 363         else
 364                 interface->udhcpc_process = process;
 365
 366         return;
 367 }
 368
 369 static void configure_interface_static(struct network *network,
 370                 struct interface *interface,
 371                 const struct interface_config *config)
 372 {
 373         int rc;
 374
 375         device_handler_status_dev_info(network->handler, interface->dev,
 376                         _("Configuring with static address (ip: %s)"),
 377                         config->static_config.address);
 378
 379         rc = process_run_simple(interface, pb_system_apps.ip,
 380                         "address", "add", config->static_config.address,
 381                         "dev", interface->name, NULL);
 382
 383
 384         if (rc) {
 385                 pb_log("failed to add address %s to interface %s\n",
 386                                 config->static_config.address,
 387                                 interface->name);
 388                 return;
 389         }
 390
 391         system_info_set_interface_address(sizeof(interface->hwaddr),
 392                                 interface->hwaddr,
 393                                 config->static_config.address);
 394
 395         /* we need the interface up before we can route through it */
 396         rc = interface_up(interface);
 397         if (rc)
 398                 return;
 399
 400         if (config->static_config.gateway)
 401                 rc = process_run_simple(interface, pb_system_apps.ip,
 402                                 "route", "add", "default",
 403                                 "via", config->static_config.gateway,
 404                                 NULL);
 405
 406         if (rc) {
 407                 pb_log("failed to add default route %s on interface %s\n",
 408                                 config->static_config.gateway,
 409                                 interface->name);
 410         }
 411
 412         if (config->static_config.url) {
 413                 pb_log("config URL %s\n", config->static_config.url);
 414                 device_handler_process_url(network->handler,
 415                                 config->static_config.url,
 416                                 mac_bytes_to_string(interface->dev,
 417                                                 interface->hwaddr,
 418                                                 sizeof(interface->hwaddr)),
 419                                 config->static_config.address);
 420         }
 421
 422         return;
 423 }
 424
 425 static void configure_interface(struct network *network,
 426                 struct interface *interface, bool up, bool link)
 427 {
 428         const struct interface_config *config = NULL;
 429
 430         if (interface->state == IFSTATE_IGNORED)
 431                 return;
 432
 433         /* old interface? check that we're still up and running */
 434         if (interface->state == IFSTATE_CONFIGURED) {
 435                 if (!up)
 436                         interface->state = IFSTATE_NEW;
 437                 else if (!link)
 438                         interface->state = IFSTATE_UP_WAITING_LINK;
 439                 else {
 440                         pb_debug("network: skipping configured interface %s\n",
 441                                         interface->name);
 442                         return;
 443                 }
 444         }
 445
 446         /* always up the lookback, no other handling required */
 447         if (!strcmp(interface->name, "lo")) {
 448                 if (interface->state == IFSTATE_NEW)
 449                         interface_up(interface);
 450                 interface->state = IFSTATE_CONFIGURED;
 451                 return;
 452         }
 453
 454         config = find_config_by_hwaddr(interface->hwaddr);
 455         if (config && config->ignore) {
 456                 pb_log("network: ignoring interface %s\n", interface->name);
 457                 interface->state = IFSTATE_IGNORED;
 458                 return;
 459         }
 460
 461         /* if we're in manual config mode, we need an interface configuration */
 462         if (network->manual_config && !config) {
 463                 interface->state = IFSTATE_IGNORED;
 464                 pb_log("network: skipping %s: manual config mode, "
 465                                 "but no config for this interface\n",
 466                                 interface->name);
 467                 return;
 468         }
 469
 470         /* new interface? bring up to the point so we can detect a link */
 471         if (interface->state == IFSTATE_NEW) {
 472                 if (!up) {
 473                         interface_up(interface);
 474                         pb_log("network: bringing up interface %s\n",
 475                                         interface->name);
 476                         return;
 477
 478                 } else if (!link) {
 479                         interface->state = IFSTATE_UP_WAITING_LINK;
 480                 }
 481         }
 482
 483         /* no link? wait for a notification */
 484         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
 485                 return;
 486
 487         pb_log("network: configuring interface %s\n", interface->name);
 488
 489         if (!config || config->method == CONFIG_METHOD_DHCP) {
 490                 configure_interface_dhcp(network, interface);
 491
 492         } else if (config->method == CONFIG_METHOD_STATIC) {
 493                 configure_interface_static(network, interface, config);
 494                 /* Nothing left to do for static interfaces */
 495                 pending_network_jobs_start();
 496         }
 497
 498         interface->state = IFSTATE_CONFIGURED;
 499 }
 500
 501 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 502 {
 503         bool have_ifaddr, have_ifname;
 504         struct interface *interface, *tmp;
 505         struct ifinfomsg *info;
 506         struct rtattr *attr;
 507         unsigned int mtu;
 508         uint8_t ifaddr[6];
 509         char ifname[IFNAMSIZ+1];
 510         int attrlen, type;
 511
 512
 513         /* we're only interested in NEWLINK messages */
 514         type = nlmsg->nlmsg_type;
 515         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
 516                 return 0;
 517
 518         info = NLMSG_DATA(nlmsg);
 519
 520         have_ifaddr = have_ifname = false;
 521         mtu = 1;
 522
 523         attrlen = nlmsg->nlmsg_len - sizeof(*info);
 524
 525         /* extract the interface name and hardware address attributes */
 526         for_each_rta(info + 1, attr, attrlen) {
 527                 void *data = RTA_DATA(attr);
 528
 529                 switch (attr->rta_type) {
 530                 case IFLA_ADDRESS:
 531                         memcpy(ifaddr, data, sizeof(ifaddr));
 532                         have_ifaddr = true;
 533                         break;
 534
 535                 case IFLA_IFNAME:
 536                         strncpy(ifname, data, IFNAMSIZ);
 537                         have_ifname = true;
 538                         break;
 539
 540                 case IFLA_MTU:
 541                         mtu = *(unsigned int *)data;
 542                         break;
 543                 }
 544         }
 545
 546         if (!have_ifaddr || !have_ifname)
 547                 return -1;
 548
 549         if (type == RTM_DELLINK || mtu == 0) {
 550                 interface = find_interface_by_ifindex(network, info->ifi_index);
 551                 if (!interface)
 552                         return 0;
 553                 pb_log("network: interface %s removed\n", interface->name);
 554                 remove_interface(network, interface);
 555                 return 0;
 556         }
 557
 558         /* ignore the default tun device in some environments */
 559         if (strncmp(ifname, "tun", strlen("tun")) == 0)
 560                 return 0;
 561
 562         interface = find_interface_by_ifindex(network, info->ifi_index);
 563         if (!interface) {
 564                 interface = talloc_zero(network, struct interface);
 565                 interface->ifindex = info->ifi_index;
 566                 interface->state = IFSTATE_NEW;
 567                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 568                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 569
 570                 list_for_each_entry(&network->interfaces, tmp, list)
 571                         if (memcmp(interface->hwaddr, tmp->hwaddr,
 572                                    sizeof(interface->hwaddr)) == 0) {
 573                                 pb_log("%s: %s has duplicate MAC address, ignoring\n",
 574                                        __func__, interface->name);
 575                                 talloc_free(interface);
 576                                 return -1;
 577                         }
 578
 579                 list_add(&network->interfaces, &interface->list);
 580                 create_interface_dev(network, interface);
 581         }
 582
 583         /* A repeated RTM_NEWLINK can represent an interface name change */
 584         if (strncmp(interface->name, ifname, IFNAMSIZ)) {
 585                 pb_debug("ifname update: %s -> %s\n", interface->name, ifname);
 586                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 587                 talloc_free(interface->dev->device->id);
 588                 interface->dev->device->id =
 589                         talloc_strdup(interface->dev->device, ifname);
 590         }
 591
 592         /* notify the sysinfo code about changes to this interface */
 593         if (strcmp(interface->name, "lo"))
 594                 system_info_register_interface(
 595                                 sizeof(interface->hwaddr),
 596                                 interface->hwaddr, interface->name,
 597                                 info->ifi_flags & IFF_LOWER_UP);
 598
 599         if (!interface->dev)
 600                 create_interface_dev(network, interface);
 601
 602         if (!interface->ready && strncmp(interface->name, "lo", strlen("lo"))) {
 603                 pb_log("%s not marked ready yet\n", interface->name);
 604                 return 0;
 605         }
 606
 607         configure_interface(network, interface,
 608                         info->ifi_flags & IFF_UP,
 609                         info->ifi_flags & IFF_LOWER_UP);
 610
 611         return 0;
 612 }
 613
 614 void network_mark_interface_ready(struct device_handler *handler,
 615                 int ifindex, const char *ifname, uint8_t *mac, int hwsize)
 616 {
 617         struct network *network = device_handler_get_network(handler);
 618         struct interface *interface, *tmp = NULL;
 619         char *macstr;
 620
 621         if (!network) {
 622                 pb_log("Network not ready - can not mark interface ready\n");
 623                 return;
 624         }
 625
 626         if (hwsize != HWADDR_SIZE)
 627                 return;
 628
 629         if (strncmp(ifname, "lo", strlen("lo")) == 0)
 630                 return;
 631
 632         interface = find_interface_by_ifindex(network, ifindex);
 633         if (!interface) {
 634                 pb_debug("Creating ready interface %d - %s\n",
 635                                 ifindex, ifname);
 636                 interface = talloc_zero(network, struct interface);
 637                 interface->ifindex = ifindex;
 638                 interface->state = IFSTATE_NEW;
 639                 memcpy(interface->hwaddr, mac, HWADDR_SIZE);
 640                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 641
 642                 list_for_each_entry(&network->interfaces, tmp, list)
 643                         if (memcmp(interface->hwaddr, tmp->hwaddr,
 644                                    sizeof(interface->hwaddr)) == 0) {
 645                                 pb_log("%s: %s has duplicate MAC address, ignoring\n",
 646                                        __func__, interface->name);
 647                                 talloc_free(interface);
 648                                 return;
 649                         }
 650
 651                 list_add(&network->interfaces, &interface->list);
 652                 create_interface_dev(network, interface);
 653         }
 654
 655         if (interface->ready) {
 656                 pb_log("%s already ready\n", interface->name);
 657                 return;
 658         }
 659
 660         if (strncmp(interface->name, ifname, strlen(ifname)) != 0) {
 661                 pb_debug("ifname update from udev: %s -> %s\n", interface->name, ifname);
 662                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 663                 talloc_free(interface->dev->device->id);
 664                 interface->dev->device->id =
 665                         talloc_strdup(interface->dev->device, ifname);
 666         }
 667
 668         if (memcmp(interface->hwaddr, mac, HWADDR_SIZE) != 0) {
 669                 macstr = mac_bytes_to_string(interface, mac, hwsize);
 670                 pb_log("Warning - new MAC for interface %d does not match: %s\n",
 671                                 ifindex, macstr);
 672                 talloc_free(macstr);
 673         }
 674
 675         pb_log("Interface %s ready\n", ifname);
 676         interface->ready = true;
 677         configure_interface(network, interface, false, false);
 678 }
 679
 680 static int network_netlink_process(void *arg)
 681 {
 682         struct network *network = arg;
 683         struct nlmsghdr *nlmsg;
 684         struct msghdr msg;
 685         struct iovec iov;
 686         unsigned int len;
 687         int rc, flags;
 688
 689         memset(&msg, 0, sizeof(msg));
 690         msg.msg_iov = &iov;
 691         msg.msg_iovlen = 1;
 692
 693         flags = MSG_PEEK;
 694
 695 retry:
 696         iov.iov_len = network->netlink_buf_size;
 697         iov.iov_base = network->netlink_buf;
 698
 699         rc = recvmsg(network->netlink_sd, &msg, flags);
 700
 701         if (rc < 0) {
 702                 perror("netlink recv header");
 703                 return -1;
 704         }
 705
 706         len = rc;
 707
 708         /* if the netlink message was larger than our buffer, realloc
 709          * before reading again */
 710         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
 711                 network->netlink_buf_size *= 2;
 712                 network->netlink_buf = talloc_realloc(network,
 713                                         network->netlink_buf,
 714                                         char *,
 715                                         network->netlink_buf_size);
 716                 goto retry;
 717         }
 718
 719         /* otherwise, we're good to read the entire message without PEEK */
 720         if (flags == MSG_PEEK) {
 721                 flags = 0;
 722                 goto retry;
 723         }
 724
 725         for_each_nlmsg(network->netlink_buf, nlmsg, len)
 726                 network_handle_nlmsg(network, nlmsg);
 727
 728         return 0;
 729 }
 730
 731 static void network_init_dns(struct network *network)
 732 {
 733         const struct config *config;
 734         unsigned int i;
 735         int rc, len;
 736         bool modified;
 737         char *buf;
 738
 739         if (network->dry_run)
 740                 return;
 741
 742         config = config_get();
 743         if (!config || !config->network.n_dns_servers)
 744                 return;
 745
 746         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
 747
 748         if (rc) {
 749                 buf = talloc_strdup(network, "");
 750                 len = 0;
 751         }
 752
 753         modified = false;
 754
 755         for (i = 0; i < config->network.n_dns_servers; i++) {
 756                 int dns_conf_len;
 757                 char *dns_conf;
 758
 759                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
 760                                 config->network.dns_servers[i]);
 761
 762                 if (strstr(buf, dns_conf)) {
 763                         talloc_free(dns_conf);
 764                         continue;
 765                 }
 766
 767                 dns_conf_len = strlen(dns_conf);
 768                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
 769                 memcpy(buf + len, dns_conf, dns_conf_len);
 770                 len += dns_conf_len;
 771                 buf[len] = '\0';
 772                 modified = true;
 773
 774                 talloc_free(dns_conf);
 775         }
 776
 777         if (modified) {
 778                 rc = replace_file("/etc/resolv.conf", buf, len);
 779                 if (rc)
 780                         pb_log("error replacing resolv.conf: %s\n",
 781                                         strerror(errno));
 782         }
 783
 784         talloc_free(buf);
 785 }
 786
 787 struct network *network_init(struct device_handler *handler,
 788                 struct waitset *waitset, bool dry_run)
 789 {
 790         struct network *network;
 791         int rc;
 792
 793         network = talloc(handler, struct network);
 794         list_init(&network->interfaces);
 795         network->handler = handler;
 796         network->dry_run = dry_run;
 797         network->manual_config = config_get()->network.n_interfaces != 0;
 798
 799         network_init_dns(network);
 800
 801         rc = network_init_netlink(network);
 802         if (rc)
 803                 goto err;
 804
 805         network->waiter = waiter_register_io(waitset, network->netlink_sd,
 806                         WAIT_IN, network_netlink_process, network);
 807
 808         if (!network->waiter)
 809                 goto err;
 810
 811         rc = network_send_link_query(network);
 812         if (rc)
 813                 goto err;
 814
 815         return network;
 816
 817 err:
 818         network_shutdown(network);
 819         return NULL;
 820 }
 821
 822 int network_shutdown(struct network *network)
 823 {
 824         struct interface *interface;
 825
 826         if (network->waiter)
 827                 waiter_remove(network->waiter);
 828
 829         list_for_each_entry(&network->interfaces, interface, list) {
 830                 if (interface->state == IFSTATE_IGNORED)
 831                         continue;
 832                 if (!strcmp(interface->name, "lo"))
 833                         continue;
 834                 interface_down(interface);
 835         }
 836
 837         close(network->netlink_sd);
 838         talloc_free(network);
 839         return 0;
 840 }