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