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