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