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         if (dev->uuid)
 246                 iface = find_interface_by_uuid(network, dev->uuid);
 247         else
 248                 iface = find_interface_by_name(network, dev->label);
 249         if (!iface)
 250                 return;
 251
 252         iface->dev = dev;
 253         dev->uuid = mac_bytes_to_string(iface->dev, iface->hwaddr,
 254                         sizeof(iface->hwaddr));
 255 }
 256
 257 void network_unregister_device(struct network *network,
 258                 struct discover_device *dev)
 259 {
 260         struct interface *iface;
 261
 262         iface = find_interface_by_uuid(network, dev->uuid);
 263         if (!iface)
 264                 return;
 265
 266         iface->dev = NULL;
 267 }
 268
 269 static int interface_change(struct interface *interface, bool up)
 270 {
 271         const char *statestr = up ? "up" : "down";
 272         int rc;
 273
 274         if (!up && interface->udhcpc_process) {
 275                 /* we don't care about the callback from here */
 276                 interface->udhcpc_process->exit_cb = NULL;
 277                 interface->udhcpc_process->data = NULL;
 278                 process_stop_async(interface->udhcpc_process);
 279                 process_release(interface->udhcpc_process);
 280         }
 281
 282         if (!up) {
 283                 rc = process_run_simple(interface, pb_system_apps.ip,
 284                                 "address", "flush", "dev", interface->name,
 285                                 NULL);
 286                 if (rc)
 287                         pb_log("failed to flush addresses from interface %s\n",
 288                                 interface->name);
 289         }
 290
 291         rc = process_run_simple(interface, pb_system_apps.ip,
 292                         "link", "set", interface->name, statestr, NULL);
 293         if (rc) {
 294                 pb_log("failed to bring interface %s %s\n", interface->name,
 295                                 statestr);
 296                 return -1;
 297         }
 298         return 0;
 299 }
 300
 301 static int interface_up(struct interface *interface)
 302 {
 303         return interface_change(interface, true);
 304 }
 305
 306 static int interface_down(struct interface *interface)
 307 {
 308         return interface_change(interface, false);
 309 }
 310
 311 static void udhcpc_process_exit(struct process *process)
 312 {
 313         struct interface *interface = process->data;
 314         pb_debug("udhcp client [pid %d] for interface %s exited, rc %d\n",
 315                         process->pid, interface->name, process->exit_status);
 316         interface->udhcpc_process = NULL;
 317         process_release(process);
 318 }
 319
 320 static void configure_interface_dhcp(struct network *network,
 321                 struct interface *interface)
 322 {
 323         const struct platform *platform;
 324         char pidfile[256], id[10];
 325         struct process *process;
 326         int rc;
 327         const char *argv[] = {
 328                 pb_system_apps.udhcpc,
 329                 "-R",
 330                 "-f",
 331                 "-O", "pxeconffile",
 332                 "-O", "pxepathprefix",
 333                 "-p", pidfile,
 334                 "-i", interface->name,
 335                 "-x", id, /* [11,12] - dhcp client identifier */
 336                 NULL,
 337         };
 338
 339         device_handler_status_dev_info(network->handler, interface->dev,
 340                         _("Configuring with DHCP"));
 341
 342         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
 343                         PIDFILE_BASE, interface->name);
 344
 345         platform = platform_get();
 346         if (platform && platform->dhcp_arch_id != 0xffff)
 347                 snprintf(id, sizeof(id), "0x5d:%04x", platform->dhcp_arch_id);
 348         else
 349                 argv[11] = NULL;
 350
 351         process = process_create(interface);
 352
 353         process->path = pb_system_apps.udhcpc;
 354         process->argv = argv;
 355         process->exit_cb = udhcpc_process_exit;
 356         process->data = interface;
 357
 358         rc = process_run_async(process);
 359
 360         if (rc)
 361                 process_release(process);
 362         else
 363                 interface->udhcpc_process = process;
 364
 365         return;
 366 }
 367
 368 static void configure_interface_static(struct network *network,
 369                 struct interface *interface,
 370                 const struct interface_config *config)
 371 {
 372         int rc;
 373
 374         device_handler_status_dev_info(network->handler, interface->dev,
 375                         _("Configuring with static address (ip: %s)"),
 376                         config->static_config.address);
 377
 378         rc = process_run_simple(interface, pb_system_apps.ip,
 379                         "address", "add", config->static_config.address,
 380                         "dev", interface->name, NULL);
 381
 382
 383         if (rc) {
 384                 pb_log("failed to add address %s to interface %s\n",
 385                                 config->static_config.address,
 386                                 interface->name);
 387                 return;
 388         }
 389
 390         system_info_set_interface_address(sizeof(interface->hwaddr),
 391                                 interface->hwaddr,
 392                                 config->static_config.address);
 393
 394         /* we need the interface up before we can route through it */
 395         rc = interface_up(interface);
 396         if (rc)
 397                 return;
 398
 399         if (config->static_config.gateway)
 400                 rc = process_run_simple(interface, pb_system_apps.ip,
 401                                 "route", "add", "default",
 402                                 "via", config->static_config.gateway,
 403                                 NULL);
 404
 405         if (rc) {
 406                 pb_log("failed to add default route %s on interface %s\n",
 407                                 config->static_config.gateway,
 408                                 interface->name);
 409         }
 410
 411         if (config->static_config.url) {
 412                 pb_log("config URL %s\n", config->static_config.url);
 413                 device_handler_process_url(network->handler,
 414                                 config->static_config.url,
 415                                 mac_bytes_to_string(interface->dev,
 416                                                 interface->hwaddr,
 417                                                 sizeof(interface->hwaddr)),
 418                                 config->static_config.address);
 419         }
 420
 421         return;
 422 }
 423
 424 static void configure_interface(struct network *network,
 425                 struct interface *interface, bool up, bool link)
 426 {
 427         const struct interface_config *config = NULL;
 428
 429         if (interface->state == IFSTATE_IGNORED)
 430                 return;
 431
 432         /* old interface? check that we're still up and running */
 433         if (interface->state == IFSTATE_CONFIGURED) {
 434                 if (!up)
 435                         interface->state = IFSTATE_NEW;
 436                 else if (!link)
 437                         interface->state = IFSTATE_UP_WAITING_LINK;
 438                 else {
 439                         pb_debug("network: skipping configured interface %s\n",
 440                                         interface->name);
 441                         return;
 442                 }
 443         }
 444
 445         /* always up the lookback, no other handling required */
 446         if (!strcmp(interface->name, "lo")) {
 447                 if (interface->state == IFSTATE_NEW)
 448                         interface_up(interface);
 449                 interface->state = IFSTATE_CONFIGURED;
 450                 return;
 451         }
 452
 453         config = find_config_by_hwaddr(interface->hwaddr);
 454         if (config && config->ignore) {
 455                 pb_log("network: ignoring interface %s\n", interface->name);
 456                 interface->state = IFSTATE_IGNORED;
 457                 return;
 458         }
 459
 460         /* if we're in manual config mode, we need an interface configuration */
 461         if (network->manual_config && !config) {
 462                 interface->state = IFSTATE_IGNORED;
 463                 pb_log("network: skipping %s: manual config mode, "
 464                                 "but no config for this interface\n",
 465                                 interface->name);
 466                 return;
 467         }
 468
 469         /* new interface? bring up to the point so we can detect a link */
 470         if (interface->state == IFSTATE_NEW) {
 471                 if (!up) {
 472                         interface_up(interface);
 473                         pb_log("network: bringing up interface %s\n",
 474                                         interface->name);
 475                         return;
 476
 477                 } else if (!link) {
 478                         interface->state = IFSTATE_UP_WAITING_LINK;
 479                 }
 480         }
 481
 482         /* no link? wait for a notification */
 483         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
 484                 return;
 485
 486         pb_log("network: configuring interface %s\n", interface->name);
 487
 488         if (!config || config->method == CONFIG_METHOD_DHCP) {
 489                 configure_interface_dhcp(network, interface);
 490
 491         } else if (config->method == CONFIG_METHOD_STATIC) {
 492                 configure_interface_static(network, interface, config);
 493         }
 494
 495         interface->state = IFSTATE_CONFIGURED;
 496 }
 497
 498 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 499 {
 500         bool have_ifaddr, have_ifname;
 501         struct interface *interface;
 502         struct ifinfomsg *info;
 503         struct rtattr *attr;
 504         unsigned int mtu;
 505         uint8_t ifaddr[6];
 506         char ifname[IFNAMSIZ+1];
 507         int attrlen, type;
 508
 509
 510         /* we're only interested in NEWLINK messages */
 511         type = nlmsg->nlmsg_type;
 512         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
 513                 return 0;
 514
 515         info = NLMSG_DATA(nlmsg);
 516
 517         have_ifaddr = have_ifname = false;
 518         mtu = 1;
 519
 520         attrlen = nlmsg->nlmsg_len - sizeof(*info);
 521
 522         /* extract the interface name and hardware address attributes */
 523         for_each_rta(info + 1, attr, attrlen) {
 524                 void *data = RTA_DATA(attr);
 525
 526                 switch (attr->rta_type) {
 527                 case IFLA_ADDRESS:
 528                         memcpy(ifaddr, data, sizeof(ifaddr));
 529                         have_ifaddr = true;
 530                         break;
 531
 532                 case IFLA_IFNAME:
 533                         strncpy(ifname, data, IFNAMSIZ);
 534                         have_ifname = true;
 535                         break;
 536
 537                 case IFLA_MTU:
 538                         mtu = *(unsigned int *)data;
 539                         break;
 540                 }
 541         }
 542
 543         if (!have_ifaddr || !have_ifname)
 544                 return -1;
 545
 546         if (type == RTM_DELLINK || mtu == 0) {
 547                 interface = find_interface_by_ifindex(network, info->ifi_index);
 548                 if (!interface)
 549                         return 0;
 550                 pb_log("network: interface %s removed\n", interface->name);
 551                 remove_interface(network, interface);
 552                 return 0;
 553         }
 554
 555         /* ignore the default tun device in some environments */
 556         if (strncmp(ifname, "tun", strlen("tun")) == 0)
 557                 return 0;
 558
 559         interface = find_interface_by_ifindex(network, info->ifi_index);
 560         if (!interface) {
 561                 interface = talloc_zero(network, struct interface);
 562                 interface->ifindex = info->ifi_index;
 563                 interface->state = IFSTATE_NEW;
 564                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 565                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 566                 add_interface(network, interface);
 567         }
 568
 569         /* A repeated RTM_NEWLINK can represent an interface name change */
 570         if (strncmp(interface->name, ifname, IFNAMSIZ)) {
 571                 pb_debug("ifname update: %s -> %s\n", interface->name, ifname);
 572                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 573                 talloc_free(interface->dev->device->id);
 574                 interface->dev->device->id =
 575                         talloc_strdup(interface->dev->device, ifname);
 576         }
 577
 578         /* notify the sysinfo code about changes to this interface */
 579         if (strcmp(interface->name, "lo"))
 580                 system_info_register_interface(
 581                                 sizeof(interface->hwaddr),
 582                                 interface->hwaddr, interface->name,
 583                                 info->ifi_flags & IFF_LOWER_UP);
 584
 585         configure_interface(network, interface,
 586                         info->ifi_flags & IFF_UP,
 587                         info->ifi_flags & IFF_LOWER_UP);
 588
 589         return 0;
 590 }
 591
 592 static int network_netlink_process(void *arg)
 593 {
 594         struct network *network = arg;
 595         struct nlmsghdr *nlmsg;
 596         struct msghdr msg;
 597         struct iovec iov;
 598         unsigned int len;
 599         int rc, flags;
 600
 601         memset(&msg, 0, sizeof(msg));
 602         msg.msg_iov = &iov;
 603         msg.msg_iovlen = 1;
 604
 605         flags = MSG_PEEK;
 606
 607 retry:
 608         iov.iov_len = network->netlink_buf_size;
 609         iov.iov_base = network->netlink_buf;
 610
 611         rc = recvmsg(network->netlink_sd, &msg, flags);
 612
 613         if (rc < 0) {
 614                 perror("netlink recv header");
 615                 return -1;
 616         }
 617
 618         len = rc;
 619
 620         /* if the netlink message was larger than our buffer, realloc
 621          * before reading again */
 622         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
 623                 network->netlink_buf_size *= 2;
 624                 network->netlink_buf = talloc_realloc(network,
 625                                         network->netlink_buf,
 626                                         char *,
 627                                         network->netlink_buf_size);
 628                 goto retry;
 629         }
 630
 631         /* otherwise, we're good to read the entire message without PEEK */
 632         if (flags == MSG_PEEK) {
 633                 flags = 0;
 634                 goto retry;
 635         }
 636
 637         for_each_nlmsg(network->netlink_buf, nlmsg, len)
 638                 network_handle_nlmsg(network, nlmsg);
 639
 640         return 0;
 641 }
 642
 643 static void network_init_dns(struct network *network)
 644 {
 645         const struct config *config;
 646         unsigned int i;
 647         int rc, len;
 648         bool modified;
 649         char *buf;
 650
 651         if (network->dry_run)
 652                 return;
 653
 654         config = config_get();
 655         if (!config || !config->network.n_dns_servers)
 656                 return;
 657
 658         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
 659
 660         if (rc) {
 661                 buf = talloc_strdup(network, "");
 662                 len = 0;
 663         }
 664
 665         modified = false;
 666
 667         for (i = 0; i < config->network.n_dns_servers; i++) {
 668                 int dns_conf_len;
 669                 char *dns_conf;
 670
 671                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
 672                                 config->network.dns_servers[i]);
 673
 674                 if (strstr(buf, dns_conf)) {
 675                         talloc_free(dns_conf);
 676                         continue;
 677                 }
 678
 679                 dns_conf_len = strlen(dns_conf);
 680                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
 681                 memcpy(buf + len, dns_conf, dns_conf_len);
 682                 len += dns_conf_len;
 683                 buf[len] = '\0';
 684                 modified = true;
 685
 686                 talloc_free(dns_conf);
 687         }
 688
 689         if (modified) {
 690                 rc = replace_file("/etc/resolv.conf", buf, len);
 691                 if (rc)
 692                         pb_log("error replacing resolv.conf: %s\n",
 693                                         strerror(errno));
 694         }
 695
 696         talloc_free(buf);
 697 }
 698
 699 struct network *network_init(struct device_handler *handler,
 700                 struct waitset *waitset, bool dry_run)
 701 {
 702         struct network *network;
 703         int rc;
 704
 705         network = talloc(handler, struct network);
 706         list_init(&network->interfaces);
 707         network->handler = handler;
 708         network->dry_run = dry_run;
 709         network->manual_config = config_get()->network.n_interfaces != 0;
 710
 711         network_init_dns(network);
 712
 713         rc = network_init_netlink(network);
 714         if (rc)
 715                 goto err;
 716
 717         network->waiter = waiter_register_io(waitset, network->netlink_sd,
 718                         WAIT_IN, network_netlink_process, network);
 719
 720         if (!network->waiter)
 721                 goto err;
 722
 723         rc = network_send_link_query(network);
 724         if (rc)
 725                 goto err;
 726
 727         return network;
 728
 729 err:
 730         network_shutdown(network);
 731         return NULL;
 732 }
 733
 734 int network_shutdown(struct network *network)
 735 {
 736         struct interface *interface;
 737
 738         if (network->waiter)
 739                 waiter_remove(network->waiter);
 740
 741         list_for_each_entry(&network->interfaces, interface, list) {
 742                 if (interface->state == IFSTATE_IGNORED)
 743                         continue;
 744                 if (!strcmp(interface->name, "lo"))
 745                         continue;
 746                 interface_down(interface);
 747         }
 748
 749         close(network->netlink_sd);
 750         talloc_free(network);
 751         return 0;
 752 }