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 int network_init_netlink(struct network *network)
 101 {
 102         struct sockaddr_nl addr;
 103         int rc;
 104
 105         memset(&addr, 0, sizeof(addr));
 106         addr.nl_family = AF_NETLINK;
 107         addr.nl_groups = RTMGRP_LINK;
 108
 109         network->netlink_sd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
 110         if (network->netlink_sd < 0) {
 111                 perror("socket(AF_NETLINK)");
 112                 return -1;
 113         }
 114
 115         rc = bind(network->netlink_sd, (struct sockaddr *)&addr, sizeof(addr));
 116         if (rc) {
 117                 perror("bind(sockaddr_nl)");
 118                 close(network->netlink_sd);
 119                 return -1;
 120         }
 121
 122         network->netlink_buf_size = INITIAL_BUFSIZE;
 123         network->netlink_buf = talloc_array(network, char,
 124                                 network->netlink_buf_size);
 125
 126         return 0;
 127 }
 128
 129 static int network_send_link_query(struct network *network)
 130 {
 131         int rc;
 132         struct {
 133                 struct nlmsghdr nlmsg;
 134                 struct rtgenmsg rtmsg;
 135         } msg;
 136
 137         memset(&msg, 0, sizeof(msg));
 138
 139         msg.nlmsg.nlmsg_len = sizeof(msg);
 140         msg.nlmsg.nlmsg_type = RTM_GETLINK;
 141         msg.nlmsg.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT;
 142         msg.nlmsg.nlmsg_seq = 0;
 143         msg.nlmsg.nlmsg_pid = 0;
 144         msg.rtmsg.rtgen_family = AF_UNSPEC;
 145
 146         rc = send(network->netlink_sd, &msg, sizeof(msg), MSG_NOSIGNAL);
 147         if (rc != sizeof(msg))
 148                 return -1;
 149
 150         return 0;
 151 }
 152
 153 static void add_interface(struct network *network,
 154                 struct interface *interface)
 155 {
 156         list_add(&network->interfaces, &interface->list);
 157         interface->dev = discover_device_create(network->handler,
 158                                         interface->name);
 159         interface->dev->device->type = DEVICE_TYPE_NETWORK;
 160         device_handler_add_device(network->handler, interface->dev);
 161 }
 162
 163 static void remove_interface(struct network *network,
 164                 struct interface *interface)
 165 {
 166         device_handler_remove(network->handler, interface->dev);
 167         list_remove(&interface->list);
 168         talloc_free(interface);
 169 }
 170
 171 static int interface_change(struct interface *interface, bool up)
 172 {
 173         const char *statestr = up ? "up" : "down";
 174         int rc;
 175
 176         if (!up && interface->udhcpc_process) {
 177                 /* we don't care about the callback from here */
 178                 interface->udhcpc_process->exit_cb = NULL;
 179                 interface->udhcpc_process->data = NULL;
 180                 process_stop_async(interface->udhcpc_process);
 181                 process_release(interface->udhcpc_process);
 182         }
 183
 184         if (!up) {
 185                 rc = process_run_simple(interface, pb_system_apps.ip,
 186                                 "address", "flush", "dev", interface->name,
 187                                 NULL);
 188                 if (rc)
 189                         pb_log("failed to flush addresses from interface %s\n",
 190                                 interface->name);
 191         }
 192
 193         rc = process_run_simple(interface, pb_system_apps.ip,
 194                         "link", "set", interface->name, statestr, NULL);
 195         if (rc) {
 196                 pb_log("failed to bring interface %s %s\n", interface->name,
 197                                 statestr);
 198                 return -1;
 199         }
 200         return 0;
 201 }
 202
 203 static int interface_up(struct interface *interface)
 204 {
 205         return interface_change(interface, true);
 206 }
 207
 208 static int interface_down(struct interface *interface)
 209 {
 210         return interface_change(interface, false);
 211 }
 212
 213 static void udhcpc_process_exit(struct process *process)
 214 {
 215         struct interface *interface = process->data;
 216         pb_debug("udhcp client [pid %d] for interface %s exited, rc %d\n",
 217                         process->pid, interface->name, process->exit_status);
 218         interface->udhcpc_process = NULL;
 219         process_release(process);
 220 }
 221
 222 static void configure_interface_dhcp(struct interface *interface)
 223 {
 224         const struct platform *platform;
 225         char pidfile[256], id[10];
 226         struct process *process;
 227         int rc;
 228         const char *argv[] = {
 229                 pb_system_apps.udhcpc,
 230                 "-R",
 231                 "-f",
 232                 "-O", "pxeconffile",
 233                 "-O", "pxepathprefix",
 234                 "-p", pidfile,
 235                 "-i", interface->name,
 236                 "-x", id, /* [11,12] - dhcp client identifier */
 237                 NULL,
 238         };
 239
 240         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
 241                         PIDFILE_BASE, interface->name);
 242
 243         platform = platform_get();
 244         if (platform && platform->dhcp_arch_id != 0xffff)
 245                 snprintf(id, sizeof(id), "0x5d:%04x", platform->dhcp_arch_id);
 246         else
 247                 argv[11] = NULL;
 248
 249         process = process_create(interface);
 250
 251         process->path = pb_system_apps.udhcpc;
 252         process->argv = argv;
 253         process->exit_cb = udhcpc_process_exit;
 254         process->data = interface;
 255
 256         rc = process_run_async(process);
 257
 258         if (rc)
 259                 process_release(process);
 260         else
 261                 interface->udhcpc_process = process;
 262
 263         return;
 264 }
 265
 266 static void configure_interface_static(struct interface *interface,
 267                 const struct interface_config *config)
 268 {
 269         int rc;
 270
 271         rc = process_run_simple(interface, pb_system_apps.ip,
 272                         "address", "add", config->static_config.address,
 273                         "dev", interface->name, NULL);
 274
 275
 276         if (rc) {
 277                 pb_log("failed to add address %s to interface %s\n",
 278                                 config->static_config.address,
 279                                 interface->name);
 280                 return;
 281         }
 282
 283         /* we need the interface up before we can route through it */
 284         rc = interface_up(interface);
 285         if (rc)
 286                 return;
 287
 288         if (config->static_config.gateway)
 289                 rc = process_run_simple(interface, pb_system_apps.ip,
 290                                 "route", "add", "default",
 291                                 "via", config->static_config.gateway,
 292                                 NULL);
 293
 294         if (rc) {
 295                 pb_log("failed to add default route %s on interface %s\n",
 296                                 config->static_config.gateway,
 297                                 interface->name);
 298         }
 299
 300         return;
 301 }
 302
 303 static void configure_interface(struct network *network,
 304                 struct interface *interface, bool up, bool link)
 305 {
 306         const struct interface_config *config = NULL;
 307
 308         if (interface->state == IFSTATE_IGNORED)
 309                 return;
 310
 311         /* old interface? check that we're still up and running */
 312         if (interface->state == IFSTATE_CONFIGURED) {
 313                 if (!up)
 314                         interface->state = IFSTATE_NEW;
 315                 else if (!link)
 316                         interface->state = IFSTATE_UP_WAITING_LINK;
 317                 else
 318                         return;
 319         }
 320
 321         /* always up the lookback, no other handling required */
 322         if (!strcmp(interface->name, "lo")) {
 323                 if (interface->state == IFSTATE_NEW)
 324                         interface_up(interface);
 325                 interface->state = IFSTATE_CONFIGURED;
 326                 return;
 327         }
 328
 329         config = find_config_by_hwaddr(interface->hwaddr);
 330         if (config && config->ignore) {
 331                 pb_log("network: ignoring interface %s\n", interface->name);
 332                 interface->state = IFSTATE_IGNORED;
 333                 return;
 334         }
 335
 336         /* if we're in manual config mode, we need an interface configuration */
 337         if (network->manual_config && !config) {
 338                 interface->state = IFSTATE_IGNORED;
 339                 pb_log("network: skipping %s: manual config mode, "
 340                                 "but no config for this interface\n",
 341                                 interface->name);
 342                 return;
 343         }
 344
 345         /* new interface? bring up to the point so we can detect a link */
 346         if (interface->state == IFSTATE_NEW) {
 347                 if (!up) {
 348                         interface_up(interface);
 349                         pb_log("network: bringing up interface %s\n",
 350                                         interface->name);
 351                         return;
 352
 353                 } else if (!link) {
 354                         interface->state = IFSTATE_UP_WAITING_LINK;
 355                 }
 356         }
 357
 358         /* no link? wait for a notification */
 359         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
 360                 return;
 361
 362         pb_log("network: configuring interface %s\n", interface->name);
 363
 364         if (!config || config->method == CONFIG_METHOD_DHCP) {
 365                 configure_interface_dhcp(interface);
 366
 367         } else if (config->method == CONFIG_METHOD_STATIC) {
 368                 configure_interface_static(interface, config);
 369         }
 370 }
 371
 372 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 373 {
 374         bool have_ifaddr, have_ifname;
 375         struct interface *interface;
 376         struct ifinfomsg *info;
 377         struct rtattr *attr;
 378         unsigned int mtu;
 379         uint8_t ifaddr[6];
 380         char ifname[IFNAMSIZ+1];
 381         int attrlen, type;
 382
 383
 384         /* we're only interested in NEWLINK messages */
 385         type = nlmsg->nlmsg_type;
 386         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
 387                 return 0;
 388
 389         info = NLMSG_DATA(nlmsg);
 390
 391         have_ifaddr = have_ifname = false;
 392         mtu = 1;
 393
 394         attrlen = nlmsg->nlmsg_len - sizeof(*info);
 395
 396         /* extract the interface name and hardware address attributes */
 397         for_each_rta(info + 1, attr, attrlen) {
 398                 void *data = RTA_DATA(attr);
 399
 400                 switch (attr->rta_type) {
 401                 case IFLA_ADDRESS:
 402                         memcpy(ifaddr, data, sizeof(ifaddr));
 403                         have_ifaddr = true;
 404                         break;
 405
 406                 case IFLA_IFNAME:
 407                         strncpy(ifname, data, IFNAMSIZ);
 408                         have_ifname = true;
 409                         break;
 410
 411                 case IFLA_MTU:
 412                         mtu = *(unsigned int *)data;
 413                         break;
 414                 }
 415         }
 416
 417         if (!have_ifaddr || !have_ifname)
 418                 return -1;
 419
 420         if (type == RTM_DELLINK || mtu == 0) {
 421                 interface = find_interface_by_ifindex(network, info->ifi_index);
 422                 if (!interface)
 423                         return 0;
 424                 pb_log("network: interface %s removed\n", interface->name);
 425                 remove_interface(network, interface);
 426                 return 0;
 427         }
 428
 429
 430         interface = find_interface_by_ifindex(network, info->ifi_index);
 431         if (!interface) {
 432                 interface = talloc_zero(network, struct interface);
 433                 interface->ifindex = info->ifi_index;
 434                 interface->state = IFSTATE_NEW;
 435                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 436                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 437                 add_interface(network, interface);
 438         }
 439
 440         /* notify the sysinfo code about changes to this interface */
 441         if (strcmp(interface->name, "lo"))
 442                 system_info_register_interface(
 443                                 sizeof(interface->hwaddr),
 444                                 interface->hwaddr, interface->name,
 445                                 info->ifi_flags & IFF_LOWER_UP);
 446
 447         configure_interface(network, interface,
 448                         info->ifi_flags & IFF_UP,
 449                         info->ifi_flags & IFF_LOWER_UP);
 450
 451         return 0;
 452 }
 453
 454 static int network_netlink_process(void *arg)
 455 {
 456         struct network *network = arg;
 457         struct nlmsghdr *nlmsg;
 458         struct msghdr msg;
 459         struct iovec iov;
 460         unsigned int len;
 461         int rc, flags;
 462
 463         memset(&msg, 0, sizeof(msg));
 464         msg.msg_iov = &iov;
 465         msg.msg_iovlen = 1;
 466
 467         flags = MSG_PEEK;
 468
 469 retry:
 470         iov.iov_len = network->netlink_buf_size;
 471         iov.iov_base = network->netlink_buf;
 472
 473         rc = recvmsg(network->netlink_sd, &msg, flags);
 474
 475         if (rc < 0) {
 476                 perror("netlink recv header");
 477                 return -1;
 478         }
 479
 480         len = rc;
 481
 482         /* if the netlink message was larger than our buffer, realloc
 483          * before reading again */
 484         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
 485                 network->netlink_buf_size *= 2;
 486                 network->netlink_buf = talloc_realloc(network,
 487                                         network->netlink_buf,
 488                                         char *,
 489                                         network->netlink_buf_size);
 490                 goto retry;
 491         }
 492
 493         /* otherwise, we're good to read the entire message without PEEK */
 494         if (flags == MSG_PEEK) {
 495                 flags = 0;
 496                 goto retry;
 497         }
 498
 499         for_each_nlmsg(network->netlink_buf, nlmsg, len)
 500                 network_handle_nlmsg(network, nlmsg);
 501
 502         return 0;
 503 }
 504
 505 static void network_init_dns(struct network *network)
 506 {
 507         const struct config *config;
 508         unsigned int i;
 509         int rc, len;
 510         bool modified;
 511         char *buf;
 512
 513         if (network->dry_run)
 514                 return;
 515
 516         config = config_get();
 517         if (!config || !config->network.n_dns_servers)
 518                 return;
 519
 520         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
 521
 522         if (rc) {
 523                 buf = talloc_strdup(network, "");
 524                 len = 0;
 525         }
 526
 527         modified = false;
 528
 529         for (i = 0; i < config->network.n_dns_servers; i++) {
 530                 int dns_conf_len;
 531                 char *dns_conf;
 532
 533                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
 534                                 config->network.dns_servers[i]);
 535
 536                 if (strstr(buf, dns_conf)) {
 537                         talloc_free(dns_conf);
 538                         continue;
 539                 }
 540
 541                 dns_conf_len = strlen(dns_conf);
 542                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
 543                 memcpy(buf + len, dns_conf, dns_conf_len);
 544                 len += dns_conf_len;
 545                 buf[len] = '\0';
 546                 modified = true;
 547
 548                 talloc_free(dns_conf);
 549         }
 550
 551         if (modified) {
 552                 rc = replace_file("/etc/resolv.conf", buf, len);
 553                 if (rc)
 554                         pb_log("error replacing resolv.conf: %s\n",
 555                                         strerror(errno));
 556         }
 557
 558         talloc_free(buf);
 559 }
 560
 561 struct network *network_init(struct device_handler *handler,
 562                 struct waitset *waitset, bool dry_run)
 563 {
 564         struct network *network;
 565         int rc;
 566
 567         network = talloc(handler, struct network);
 568         list_init(&network->interfaces);
 569         network->handler = handler;
 570         network->dry_run = dry_run;
 571         network->manual_config = config_get()->network.n_interfaces != 0;
 572
 573         network_init_dns(network);
 574
 575         rc = network_init_netlink(network);
 576         if (rc)
 577                 goto err;
 578
 579         network->waiter = waiter_register_io(waitset, network->netlink_sd,
 580                         WAIT_IN, network_netlink_process, network);
 581
 582         if (!network->waiter)
 583                 goto err;
 584
 585         rc = network_send_link_query(network);
 586         if (rc)
 587                 goto err;
 588
 589         return network;
 590
 591 err:
 592         network_shutdown(network);
 593         return NULL;
 594 }
 595
 596 int network_shutdown(struct network *network)
 597 {
 598         struct interface *interface;
 599
 600         if (network->waiter)
 601                 waiter_remove(network->waiter);
 602
 603         list_for_each_entry(&network->interfaces, interface, list) {
 604                 if (interface->state == IFSTATE_IGNORED)
 605                         continue;
 606                 if (!strcmp(interface->name, "lo"))
 607                         continue;
 608                 interface_down(interface);
 609         }
 610
 611         close(network->netlink_sd);
 612         talloc_free(network);
 613         return 0;
 614 }