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 <pb-config/pb-config.h>
  18 #include <process/process.h>
  19 #include <system/system.h>
  20
  21 #include "file.h"
  22 #include "network.h"
  23 #include "sysinfo.h"
  24 #include "device-handler.h"
  25
  26 #define HWADDR_SIZE     6
  27 #define PIDFILE_BASE    (LOCAL_STATE_DIR "/petitboot/")
  28
  29 #define for_each_nlmsg(buf, nlmsg, len) \
  30         for (nlmsg = (struct nlmsghdr *)buf; \
  31                 NLMSG_OK(nlmsg, len) && nlmsg->nlmsg_type != NLMSG_DONE; \
  32                 nlmsg = NLMSG_NEXT(nlmsg, len))
  33
  34 #define for_each_rta(buf, rta, attrlen) \
  35         for (rta = (struct rtattr *)(buf); RTA_OK(rta, attrlen); \
  36                         rta = RTA_NEXT(rta, attrlen))
  37
  38
  39 struct interface {
  40         int     ifindex;
  41         char    name[IFNAMSIZ];
  42         uint8_t hwaddr[HWADDR_SIZE];
  43
  44         enum {
  45                 IFSTATE_NEW,
  46                 IFSTATE_UP_WAITING_LINK,
  47                 IFSTATE_CONFIGURED,
  48                 IFSTATE_IGNORED,
  49         } state;
  50
  51         struct list_item list;
  52         struct process *udhcpc_process;
  53         struct discover_device *dev;
  54 };
  55
  56 struct network {
  57         struct list             interfaces;
  58         struct device_handler   *handler;
  59         struct waiter           *waiter;
  60         int                     netlink_sd;
  61         bool                    manual_config;
  62         bool                    dry_run;
  63 };
  64
  65 static const struct interface_config *find_config_by_hwaddr(
  66                 uint8_t *hwaddr)
  67 {
  68         const struct config *config;
  69         int i;
  70
  71         config = config_get();
  72         if (!config)
  73                 return NULL;
  74
  75         for (i = 0; i < config->network.n_interfaces; i++) {
  76                 struct interface_config *ifconf = config->network.interfaces[i];
  77
  78                 if (!memcmp(ifconf->hwaddr, hwaddr, HWADDR_SIZE))
  79                         return ifconf;
  80         }
  81
  82         return NULL;
  83 }
  84
  85 static struct interface *find_interface_by_ifindex(struct network *network,
  86                 int ifindex)
  87 {
  88         struct interface *interface;
  89
  90         list_for_each_entry(&network->interfaces, interface, list)
  91                 if (interface->ifindex == ifindex)
  92                         return interface;
  93
  94         return NULL;
  95 }
  96
  97 static int network_init_netlink(struct network *network)
  98 {
  99         struct sockaddr_nl addr;
 100         int rc;
 101
 102         memset(&addr, 0, sizeof(addr));
 103         addr.nl_family = AF_NETLINK;
 104         addr.nl_groups = RTMGRP_LINK;
 105
 106         network->netlink_sd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
 107         if (network->netlink_sd < 0) {
 108                 perror("socket(AF_NETLINK)");
 109                 return -1;
 110         }
 111
 112         rc = bind(network->netlink_sd, (struct sockaddr *)&addr, sizeof(addr));
 113         if (rc) {
 114                 perror("bind(sockaddr_nl)");
 115                 close(network->netlink_sd);
 116                 return -1;
 117         }
 118
 119         return 0;
 120 }
 121
 122 static int network_send_link_query(struct network *network)
 123 {
 124         int rc;
 125         struct {
 126                 struct nlmsghdr nlmsg;
 127                 struct rtgenmsg rtmsg;
 128         } msg;
 129
 130         memset(&msg, 0, sizeof(msg));
 131
 132         msg.nlmsg.nlmsg_len = sizeof(msg);
 133         msg.nlmsg.nlmsg_type = RTM_GETLINK;
 134         msg.nlmsg.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT;
 135         msg.nlmsg.nlmsg_seq = 0;
 136         msg.nlmsg.nlmsg_pid = 0;
 137         msg.rtmsg.rtgen_family = AF_UNSPEC;
 138
 139         rc = send(network->netlink_sd, &msg, sizeof(msg), MSG_NOSIGNAL);
 140         if (rc != sizeof(msg))
 141                 return -1;
 142
 143         return 0;
 144 }
 145
 146 static void add_interface(struct network *network,
 147                 struct interface *interface)
 148 {
 149         list_add(&network->interfaces, &interface->list);
 150         interface->dev = discover_device_create(network->handler,
 151                                         interface->name);
 152         interface->dev->device->type = DEVICE_TYPE_NETWORK;
 153         device_handler_add_device(network->handler, interface->dev);
 154 }
 155
 156 static void remove_interface(struct network *network,
 157                 struct interface *interface)
 158 {
 159         device_handler_remove(network->handler, interface->dev);
 160         list_remove(&interface->list);
 161         talloc_free(interface);
 162 }
 163
 164 static int interface_change(struct interface *interface, bool up)
 165 {
 166         const char *statestr = up ? "up" : "down";
 167         int rc;
 168
 169         if (!up && interface->udhcpc_process) {
 170                 /* we don't care about the callback from here */
 171                 interface->udhcpc_process->exit_cb = NULL;
 172                 interface->udhcpc_process->data = NULL;
 173                 process_stop_async(interface->udhcpc_process);
 174                 process_release(interface->udhcpc_process);
 175         }
 176
 177         rc = process_run_simple(interface, pb_system_apps.ip,
 178                         "link", "set", interface->name, statestr, NULL);
 179         if (rc) {
 180                 pb_log("failed to bring interface %s %s\n", interface->name,
 181                                 statestr);
 182                 return -1;
 183         }
 184         return 0;
 185 }
 186
 187 static int interface_up(struct interface *interface)
 188 {
 189         return interface_change(interface, true);
 190 }
 191
 192 static int interface_down(struct interface *interface)
 193 {
 194         return interface_change(interface, false);
 195 }
 196
 197 static void udhcpc_process_exit(struct process *process)
 198 {
 199         struct interface *interface = process->data;
 200         pb_log("udhcp client [pid %d] for interface %s exited, rc %d\n",
 201                         process->pid, interface->name, process->exit_status);
 202         interface->udhcpc_process = NULL;
 203         process_release(process);
 204 }
 205
 206 static void configure_interface_dhcp(struct interface *interface)
 207 {
 208         struct process *process;
 209         char pidfile[256];
 210         int rc;
 211         const char *argv[] = {
 212                 pb_system_apps.udhcpc,
 213                 "-R",
 214                 "-n",
 215                 "-p", pidfile,
 216                 "-i", interface->name,
 217                 NULL,
 218         };
 219         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
 220                         PIDFILE_BASE, interface->name);
 221
 222         process = process_create(interface);
 223
 224         process->path = pb_system_apps.udhcpc;
 225         process->argv = argv;
 226         process->exit_cb = udhcpc_process_exit;
 227         process->data = interface;
 228
 229         rc = process_run_async(process);
 230
 231         if (rc)
 232                 process_release(process);
 233         else
 234                 interface->udhcpc_process = process;
 235
 236         return;
 237 }
 238
 239 static void configure_interface_static(struct interface *interface,
 240                 const struct interface_config *config)
 241 {
 242         int rc;
 243
 244         rc = process_run_simple(interface, pb_system_apps.ip,
 245                         "address", "add", config->static_config.address,
 246                         "dev", interface->name, NULL);
 247
 248
 249         if (rc) {
 250                 pb_log("failed to add address %s to interface %s\n",
 251                                 config->static_config.address,
 252                                 interface->name);
 253                 return;
 254         }
 255
 256         /* we need the interface up before we can route through it */
 257         rc = interface_up(interface);
 258         if (rc)
 259                 return;
 260
 261         if (config->static_config.gateway)
 262                 rc = process_run_simple(interface, pb_system_apps.ip,
 263                                 "route", "add", "default",
 264                                 "via", config->static_config.gateway,
 265                                 NULL);
 266
 267         if (rc) {
 268                 pb_log("failed to add default route %s on interface %s\n",
 269                                 config->static_config.gateway,
 270                                 interface->name);
 271         }
 272
 273         return;
 274 }
 275
 276 static void configure_interface(struct network *network,
 277                 struct interface *interface, bool up, bool link)
 278 {
 279         const struct interface_config *config = NULL;
 280
 281         if (interface->state == IFSTATE_IGNORED)
 282                 return;
 283
 284         /* old interface? check that we're still up and running */
 285         if (interface->state == IFSTATE_CONFIGURED) {
 286                 if (!up)
 287                         interface->state = IFSTATE_NEW;
 288                 else if (!link)
 289                         interface->state = IFSTATE_UP_WAITING_LINK;
 290                 else
 291                         return;
 292         }
 293
 294         /* always up the lookback, no other handling required */
 295         if (!strcmp(interface->name, "lo")) {
 296                 if (interface->state == IFSTATE_NEW)
 297                         interface_up(interface);
 298                 interface->state = IFSTATE_CONFIGURED;
 299                 return;
 300         }
 301
 302         config = find_config_by_hwaddr(interface->hwaddr);
 303         if (config && config->ignore) {
 304                 pb_log("network: ignoring interface %s\n", interface->name);
 305                 interface->state = IFSTATE_IGNORED;
 306                 return;
 307         }
 308
 309         /* if we're in manual config mode, we need an interface configuration */
 310         if (network->manual_config && !config) {
 311                 interface->state = IFSTATE_IGNORED;
 312                 pb_log("network: skipping %s: manual config mode, "
 313                                 "but no config for this interface\n",
 314                                 interface->name);
 315                 return;
 316         }
 317
 318         /* new interface? bring up to the point so we can detect a link */
 319         if (interface->state == IFSTATE_NEW) {
 320                 if (!up) {
 321                         interface_up(interface);
 322                         pb_log("network: bringing up interface %s\n",
 323                                         interface->name);
 324                         return;
 325
 326                 } else if (!link) {
 327                         interface->state = IFSTATE_UP_WAITING_LINK;
 328                 }
 329         }
 330
 331         /* no link? wait for a notification */
 332         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
 333                 return;
 334
 335         pb_log("network: configuring interface %s\n", interface->name);
 336
 337         if (!config || config->method == CONFIG_METHOD_DHCP) {
 338                 configure_interface_dhcp(interface);
 339
 340         } else if (config->method == CONFIG_METHOD_STATIC) {
 341                 configure_interface_static(interface, config);
 342         }
 343 }
 344
 345 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 346 {
 347         bool have_ifaddr, have_ifname;
 348         struct interface *interface;
 349         struct ifinfomsg *info;
 350         struct rtattr *attr;
 351         unsigned int mtu;
 352         uint8_t ifaddr[6];
 353         char ifname[IFNAMSIZ+1];
 354         int attrlen, type;
 355
 356
 357         /* we're only interested in NEWLINK messages */
 358         type = nlmsg->nlmsg_type;
 359         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
 360                 return 0;
 361
 362         info = NLMSG_DATA(nlmsg);
 363
 364         have_ifaddr = have_ifname = false;
 365
 366         attrlen = nlmsg->nlmsg_len - sizeof(*info);
 367
 368         /* extract the interface name and hardware address attributes */
 369         for_each_rta(info + 1, attr, attrlen) {
 370                 void *data = RTA_DATA(attr);
 371
 372                 switch (attr->rta_type) {
 373                 case IFLA_ADDRESS:
 374                         memcpy(ifaddr, data, sizeof(ifaddr));
 375                         have_ifaddr = true;
 376                         break;
 377
 378                 case IFLA_IFNAME:
 379                         strncpy(ifname, data, IFNAMSIZ);
 380                         have_ifname = true;
 381                         break;
 382
 383                 case IFLA_MTU:
 384                         mtu = *(unsigned int *)data;
 385                         break;
 386                 }
 387         }
 388
 389         if (!have_ifaddr || !have_ifname)
 390                 return -1;
 391
 392         if (type == RTM_DELLINK || mtu == 0) {
 393                 interface = find_interface_by_ifindex(network, info->ifi_index);
 394                 if (!interface)
 395                         return 0;
 396                 pb_log("network: interface %s removed\n", interface->name);
 397                 remove_interface(network, interface);
 398                 return 0;
 399         }
 400
 401
 402         interface = find_interface_by_ifindex(network, info->ifi_index);
 403         if (!interface) {
 404                 interface = talloc_zero(network, struct interface);
 405                 interface->ifindex = info->ifi_index;
 406                 interface->state = IFSTATE_NEW;
 407                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 408                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 409                 add_interface(network, interface);
 410
 411                 /* tell the sysinfo code about this interface */
 412                 if (strcmp(interface->name, "lo"))
 413                         system_info_register_interface(
 414                                         sizeof(interface->hwaddr),
 415                                         interface->hwaddr, interface->name);
 416         }
 417
 418         configure_interface(network, interface,
 419                         info->ifi_flags & IFF_UP,
 420                         info->ifi_flags & IFF_LOWER_UP);
 421
 422         return 0;
 423 }
 424
 425 static int network_netlink_process(void *arg)
 426 {
 427         struct network *network = arg;
 428         struct nlmsghdr *nlmsg;
 429         unsigned int len;
 430         char buf[4096];
 431         int rc;
 432
 433         rc = recv(network->netlink_sd, buf, sizeof(buf), 0);
 434         if (rc < 0) {
 435                 perror("netlink recv");
 436                 return -1;
 437         }
 438
 439         len = rc;
 440
 441         for_each_nlmsg(buf, nlmsg, len)
 442                 network_handle_nlmsg(network, nlmsg);
 443
 444         return 0;
 445 }
 446
 447 static void network_init_dns(struct network *network)
 448 {
 449         const struct config *config;
 450         int i, rc, len;
 451         bool modified;
 452         char *buf;
 453
 454         if (network->dry_run)
 455                 return;
 456
 457         config = config_get();
 458         if (!config || !config->network.n_dns_servers)
 459                 return;
 460
 461         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
 462
 463         if (rc) {
 464                 buf = talloc_strdup(network, "");
 465                 len = 0;
 466         }
 467
 468         modified = false;
 469
 470         for (i = 0; i < config->network.n_dns_servers; i++) {
 471                 int dns_conf_len;
 472                 char *dns_conf;
 473
 474                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
 475                                 config->network.dns_servers[i]);
 476
 477                 if (strstr(buf, dns_conf)) {
 478                         talloc_free(dns_conf);
 479                         continue;
 480                 }
 481
 482                 dns_conf_len = strlen(dns_conf);
 483                 buf = talloc_realloc(network, buf, char, len + dns_conf_len);
 484                 memcpy(buf + len, dns_conf, dns_conf_len);
 485                 len += dns_conf_len;
 486                 modified = true;
 487
 488                 talloc_free(dns_conf);
 489         }
 490
 491         if (modified) {
 492                 rc = replace_file("/etc/resolv.conf", buf, len);
 493                 if (rc)
 494                         pb_log("error replacing resolv.conf: %s\n",
 495                                         strerror(errno));
 496         }
 497
 498         talloc_free(buf);
 499 }
 500
 501 struct network *network_init(struct device_handler *handler,
 502                 struct waitset *waitset, bool dry_run)
 503 {
 504         struct network *network;
 505         int rc;
 506
 507         network = talloc(handler, struct network);
 508         list_init(&network->interfaces);
 509         network->handler = handler;
 510         network->manual_config = false;
 511         network->dry_run = dry_run;
 512
 513         network_init_dns(network);
 514
 515         rc = network_init_netlink(network);
 516         if (rc)
 517                 goto err;
 518
 519         network->waiter = waiter_register_io(waitset, network->netlink_sd,
 520                         WAIT_IN, network_netlink_process, network);
 521
 522         if (!network->waiter)
 523                 goto err;
 524
 525         rc = network_send_link_query(network);
 526         if (rc)
 527                 goto err;
 528
 529         return network;
 530
 531 err:
 532         network_shutdown(network);
 533         return NULL;
 534 }
 535
 536
 537 int network_shutdown(struct network *network)
 538 {
 539         struct interface *interface;
 540
 541         if (network->waiter)
 542                 waiter_remove(network->waiter);
 543
 544         list_for_each_entry(&network->interfaces, interface, list)
 545                 interface_down(interface);
 546
 547         close(network->netlink_sd);
 548         talloc_free(network);
 549         return 0;
 550 }