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