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         list_add(&network->interfaces, &interface->list);
 201         interface->dev = discover_device_create(network->handler,
 202                                         interface->name);
 203         interface->dev->device->type = DEVICE_TYPE_NETWORK;
 204         interface->dev->uuid = mac_bytes_to_string(interface->dev,
 205                         interface->hwaddr, sizeof(interface->hwaddr));
 206         device_handler_add_device(network->handler, interface->dev);
 207 }
 208
 209 static void remove_interface(struct network *network,
 210                 struct interface *interface)
 211 {
 212         if (interface->dev)
 213                 device_handler_remove(network->handler, interface->dev);
 214         list_remove(&interface->list);
 215         talloc_free(interface);
 216 }
 217
 218 void network_register_device(struct network *network,
 219                 struct discover_device *dev)
 220 {
 221         struct interface *iface;
 222
 223         iface = find_interface_by_name(network, dev->device->id);
 224         if (!iface)
 225                 return;
 226
 227         iface->dev = dev;
 228         dev->uuid = mac_bytes_to_string(iface->dev, iface->hwaddr,
 229                         sizeof(iface->hwaddr));
 230 }
 231
 232 void network_unregister_device(struct network *network,
 233                 struct discover_device *dev)
 234 {
 235         struct interface *iface;
 236
 237         iface = find_interface_by_name(network, dev->device->id);
 238         if (!iface)
 239                 return;
 240
 241         iface->dev = NULL;
 242 }
 243
 244 static int interface_change(struct interface *interface, bool up)
 245 {
 246         const char *statestr = up ? "up" : "down";
 247         int rc;
 248
 249         if (!up && interface->udhcpc_process) {
 250                 /* we don't care about the callback from here */
 251                 interface->udhcpc_process->exit_cb = NULL;
 252                 interface->udhcpc_process->data = NULL;
 253                 process_stop_async(interface->udhcpc_process);
 254                 process_release(interface->udhcpc_process);
 255         }
 256
 257         if (!up) {
 258                 rc = process_run_simple(interface, pb_system_apps.ip,
 259                                 "address", "flush", "dev", interface->name,
 260                                 NULL);
 261                 if (rc)
 262                         pb_log("failed to flush addresses from interface %s\n",
 263                                 interface->name);
 264         }
 265
 266         rc = process_run_simple(interface, pb_system_apps.ip,
 267                         "link", "set", interface->name, statestr, NULL);
 268         if (rc) {
 269                 pb_log("failed to bring interface %s %s\n", interface->name,
 270                                 statestr);
 271                 return -1;
 272         }
 273         return 0;
 274 }
 275
 276 static int interface_up(struct interface *interface)
 277 {
 278         return interface_change(interface, true);
 279 }
 280
 281 static int interface_down(struct interface *interface)
 282 {
 283         return interface_change(interface, false);
 284 }
 285
 286 static void udhcpc_process_exit(struct process *process)
 287 {
 288         struct interface *interface = process->data;
 289         pb_debug("udhcp client [pid %d] for interface %s exited, rc %d\n",
 290                         process->pid, interface->name, process->exit_status);
 291         interface->udhcpc_process = NULL;
 292         process_release(process);
 293 }
 294
 295 static void configure_interface_dhcp(struct interface *interface)
 296 {
 297         const struct platform *platform;
 298         char pidfile[256], id[10];
 299         struct process *process;
 300         int rc;
 301         const char *argv[] = {
 302                 pb_system_apps.udhcpc,
 303                 "-R",
 304                 "-f",
 305                 "-O", "pxeconffile",
 306                 "-O", "pxepathprefix",
 307                 "-p", pidfile,
 308                 "-i", interface->name,
 309                 "-x", id, /* [11,12] - dhcp client identifier */
 310                 NULL,
 311         };
 312
 313         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
 314                         PIDFILE_BASE, interface->name);
 315
 316         platform = platform_get();
 317         if (platform && platform->dhcp_arch_id != 0xffff)
 318                 snprintf(id, sizeof(id), "0x5d:%04x", platform->dhcp_arch_id);
 319         else
 320                 argv[11] = NULL;
 321
 322         process = process_create(interface);
 323
 324         process->path = pb_system_apps.udhcpc;
 325         process->argv = argv;
 326         process->exit_cb = udhcpc_process_exit;
 327         process->data = interface;
 328
 329         rc = process_run_async(process);
 330
 331         if (rc)
 332                 process_release(process);
 333         else
 334                 interface->udhcpc_process = process;
 335
 336         return;
 337 }
 338
 339 static void configure_interface_static(struct network *network,
 340                 struct interface *interface,
 341                 const struct interface_config *config)
 342 {
 343         int rc;
 344
 345         rc = process_run_simple(interface, pb_system_apps.ip,
 346                         "address", "add", config->static_config.address,
 347                         "dev", interface->name, NULL);
 348
 349
 350         if (rc) {
 351                 pb_log("failed to add address %s to interface %s\n",
 352                                 config->static_config.address,
 353                                 interface->name);
 354                 return;
 355         }
 356
 357         /* we need the interface up before we can route through it */
 358         rc = interface_up(interface);
 359         if (rc)
 360                 return;
 361
 362         if (config->static_config.gateway)
 363                 rc = process_run_simple(interface, pb_system_apps.ip,
 364                                 "route", "add", "default",
 365                                 "via", config->static_config.gateway,
 366                                 NULL);
 367
 368         if (rc) {
 369                 pb_log("failed to add default route %s on interface %s\n",
 370                                 config->static_config.gateway,
 371                                 interface->name);
 372         }
 373
 374         if (config->static_config.url) {
 375                 pb_log("config URL %s\n", config->static_config.url);
 376                 device_handler_process_url(network->handler,
 377                                 config->static_config.url,
 378                                 mac_bytes_to_string(interface->dev,
 379                                                 interface->hwaddr,
 380                                                 sizeof(interface->hwaddr)),
 381                                 config->static_config.address);
 382         }
 383
 384         return;
 385 }
 386
 387 static void configure_interface(struct network *network,
 388                 struct interface *interface, bool up, bool link)
 389 {
 390         const struct interface_config *config = NULL;
 391
 392         if (interface->state == IFSTATE_IGNORED)
 393                 return;
 394
 395         /* old interface? check that we're still up and running */
 396         if (interface->state == IFSTATE_CONFIGURED) {
 397                 if (!up)
 398                         interface->state = IFSTATE_NEW;
 399                 else if (!link)
 400                         interface->state = IFSTATE_UP_WAITING_LINK;
 401                 else {
 402                         pb_debug("network: skipping configured interface %s\n",
 403                                         interface->name);
 404                         return;
 405                 }
 406         }
 407
 408         /* always up the lookback, no other handling required */
 409         if (!strcmp(interface->name, "lo")) {
 410                 if (interface->state == IFSTATE_NEW)
 411                         interface_up(interface);
 412                 interface->state = IFSTATE_CONFIGURED;
 413                 return;
 414         }
 415
 416         config = find_config_by_hwaddr(interface->hwaddr);
 417         if (config && config->ignore) {
 418                 pb_log("network: ignoring interface %s\n", interface->name);
 419                 interface->state = IFSTATE_IGNORED;
 420                 return;
 421         }
 422
 423         /* if we're in manual config mode, we need an interface configuration */
 424         if (network->manual_config && !config) {
 425                 interface->state = IFSTATE_IGNORED;
 426                 pb_log("network: skipping %s: manual config mode, "
 427                                 "but no config for this interface\n",
 428                                 interface->name);
 429                 return;
 430         }
 431
 432         /* new interface? bring up to the point so we can detect a link */
 433         if (interface->state == IFSTATE_NEW) {
 434                 if (!up) {
 435                         interface_up(interface);
 436                         pb_log("network: bringing up interface %s\n",
 437                                         interface->name);
 438                         return;
 439
 440                 } else if (!link) {
 441                         interface->state = IFSTATE_UP_WAITING_LINK;
 442                 }
 443         }
 444
 445         /* no link? wait for a notification */
 446         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
 447                 return;
 448
 449         pb_log("network: configuring interface %s\n", interface->name);
 450
 451         if (!config || config->method == CONFIG_METHOD_DHCP) {
 452                 configure_interface_dhcp(interface);
 453
 454         } else if (config->method == CONFIG_METHOD_STATIC) {
 455                 configure_interface_static(network, interface, config);
 456         }
 457
 458         interface->state = IFSTATE_CONFIGURED;
 459 }
 460
 461 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 462 {
 463         bool have_ifaddr, have_ifname;
 464         struct interface *interface;
 465         struct ifinfomsg *info;
 466         struct rtattr *attr;
 467         unsigned int mtu;
 468         uint8_t ifaddr[6];
 469         char ifname[IFNAMSIZ+1];
 470         int attrlen, type;
 471
 472
 473         /* we're only interested in NEWLINK messages */
 474         type = nlmsg->nlmsg_type;
 475         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
 476                 return 0;
 477
 478         info = NLMSG_DATA(nlmsg);
 479
 480         have_ifaddr = have_ifname = false;
 481         mtu = 1;
 482
 483         attrlen = nlmsg->nlmsg_len - sizeof(*info);
 484
 485         /* extract the interface name and hardware address attributes */
 486         for_each_rta(info + 1, attr, attrlen) {
 487                 void *data = RTA_DATA(attr);
 488
 489                 switch (attr->rta_type) {
 490                 case IFLA_ADDRESS:
 491                         memcpy(ifaddr, data, sizeof(ifaddr));
 492                         have_ifaddr = true;
 493                         break;
 494
 495                 case IFLA_IFNAME:
 496                         strncpy(ifname, data, IFNAMSIZ);
 497                         have_ifname = true;
 498                         break;
 499
 500                 case IFLA_MTU:
 501                         mtu = *(unsigned int *)data;
 502                         break;
 503                 }
 504         }
 505
 506         if (!have_ifaddr || !have_ifname)
 507                 return -1;
 508
 509         if (type == RTM_DELLINK || mtu == 0) {
 510                 interface = find_interface_by_ifindex(network, info->ifi_index);
 511                 if (!interface)
 512                         return 0;
 513                 pb_log("network: interface %s removed\n", interface->name);
 514                 remove_interface(network, interface);
 515                 return 0;
 516         }
 517
 518         /* ignore the default tun device in some environments */
 519         if (strncmp(ifname, "tun", strlen("tun")) == 0)
 520                 return 0;
 521
 522         interface = find_interface_by_ifindex(network, info->ifi_index);
 523         if (!interface) {
 524                 interface = talloc_zero(network, struct interface);
 525                 interface->ifindex = info->ifi_index;
 526                 interface->state = IFSTATE_NEW;
 527                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 528                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 529                 add_interface(network, interface);
 530         }
 531
 532         /* A repeated RTM_NEWLINK can represent an interface name change */
 533         if (strncmp(interface->name, ifname, IFNAMSIZ)) {
 534                 pb_debug("ifname update: %s -> %s\n", interface->name, ifname);
 535                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 536                 talloc_free(interface->dev->device->id);
 537                 interface->dev->device->id =
 538                         talloc_strdup(interface->dev->device, ifname);
 539         }
 540
 541         /* notify the sysinfo code about changes to this interface */
 542         if (strcmp(interface->name, "lo"))
 543                 system_info_register_interface(
 544                                 sizeof(interface->hwaddr),
 545                                 interface->hwaddr, interface->name,
 546                                 info->ifi_flags & IFF_LOWER_UP);
 547
 548         configure_interface(network, interface,
 549                         info->ifi_flags & IFF_UP,
 550                         info->ifi_flags & IFF_LOWER_UP);
 551
 552         return 0;
 553 }
 554
 555 static int network_netlink_process(void *arg)
 556 {
 557         struct network *network = arg;
 558         struct nlmsghdr *nlmsg;
 559         struct msghdr msg;
 560         struct iovec iov;
 561         unsigned int len;
 562         int rc, flags;
 563
 564         memset(&msg, 0, sizeof(msg));
 565         msg.msg_iov = &iov;
 566         msg.msg_iovlen = 1;
 567
 568         flags = MSG_PEEK;
 569
 570 retry:
 571         iov.iov_len = network->netlink_buf_size;
 572         iov.iov_base = network->netlink_buf;
 573
 574         rc = recvmsg(network->netlink_sd, &msg, flags);
 575
 576         if (rc < 0) {
 577                 perror("netlink recv header");
 578                 return -1;
 579         }
 580
 581         len = rc;
 582
 583         /* if the netlink message was larger than our buffer, realloc
 584          * before reading again */
 585         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
 586                 network->netlink_buf_size *= 2;
 587                 network->netlink_buf = talloc_realloc(network,
 588                                         network->netlink_buf,
 589                                         char *,
 590                                         network->netlink_buf_size);
 591                 goto retry;
 592         }
 593
 594         /* otherwise, we're good to read the entire message without PEEK */
 595         if (flags == MSG_PEEK) {
 596                 flags = 0;
 597                 goto retry;
 598         }
 599
 600         for_each_nlmsg(network->netlink_buf, nlmsg, len)
 601                 network_handle_nlmsg(network, nlmsg);
 602
 603         return 0;
 604 }
 605
 606 static void network_init_dns(struct network *network)
 607 {
 608         const struct config *config;
 609         unsigned int i;
 610         int rc, len;
 611         bool modified;
 612         char *buf;
 613
 614         if (network->dry_run)
 615                 return;
 616
 617         config = config_get();
 618         if (!config || !config->network.n_dns_servers)
 619                 return;
 620
 621         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
 622
 623         if (rc) {
 624                 buf = talloc_strdup(network, "");
 625                 len = 0;
 626         }
 627
 628         modified = false;
 629
 630         for (i = 0; i < config->network.n_dns_servers; i++) {
 631                 int dns_conf_len;
 632                 char *dns_conf;
 633
 634                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
 635                                 config->network.dns_servers[i]);
 636
 637                 if (strstr(buf, dns_conf)) {
 638                         talloc_free(dns_conf);
 639                         continue;
 640                 }
 641
 642                 dns_conf_len = strlen(dns_conf);
 643                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
 644                 memcpy(buf + len, dns_conf, dns_conf_len);
 645                 len += dns_conf_len;
 646                 buf[len] = '\0';
 647                 modified = true;
 648
 649                 talloc_free(dns_conf);
 650         }
 651
 652         if (modified) {
 653                 rc = replace_file("/etc/resolv.conf", buf, len);
 654                 if (rc)
 655                         pb_log("error replacing resolv.conf: %s\n",
 656                                         strerror(errno));
 657         }
 658
 659         talloc_free(buf);
 660 }
 661
 662 struct network *network_init(struct device_handler *handler,
 663                 struct waitset *waitset, bool dry_run)
 664 {
 665         struct network *network;
 666         int rc;
 667
 668         network = talloc(handler, struct network);
 669         list_init(&network->interfaces);
 670         network->handler = handler;
 671         network->dry_run = dry_run;
 672         network->manual_config = config_get()->network.n_interfaces != 0;
 673
 674         network_init_dns(network);
 675
 676         rc = network_init_netlink(network);
 677         if (rc)
 678                 goto err;
 679
 680         network->waiter = waiter_register_io(waitset, network->netlink_sd,
 681                         WAIT_IN, network_netlink_process, network);
 682
 683         if (!network->waiter)
 684                 goto err;
 685
 686         rc = network_send_link_query(network);
 687         if (rc)
 688                 goto err;
 689
 690         return network;
 691
 692 err:
 693         network_shutdown(network);
 694         return NULL;
 695 }
 696
 697 int network_shutdown(struct network *network)
 698 {
 699         struct interface *interface;
 700
 701         if (network->waiter)
 702                 waiter_remove(network->waiter);
 703
 704         list_for_each_entry(&network->interfaces, interface, list) {
 705                 if (interface->state == IFSTATE_IGNORED)
 706                         continue;
 707                 if (!strcmp(interface->name, "lo"))
 708                         continue;
 709                 interface_down(interface);
 710         }
 711
 712         close(network->netlink_sd);
 713         talloc_free(network);
 714         return 0;
 715 }