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