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