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 char *mac_bytes_to_string(void *ctx, uint8_t *addr, int len)
 154 {
 155         const int l = strlen("xx:");
 156         char *buf;
 157         int i;
 158
 159         if (len <= 0)
 160                 return talloc_strdup(ctx, "");
 161
 162         buf = talloc_array(ctx, char, (len * l) + 1);
 163
 164         for (i = 0; i < len; i++)
 165                 sprintf(buf + (l * i), "%02x:", addr[i]);
 166
 167         *(buf + (l * len) - 1) = '\0';
 168
 169         return buf;
 170 }
 171
 172 static void add_interface(struct network *network,
 173                 struct interface *interface)
 174 {
 175         list_add(&network->interfaces, &interface->list);
 176         interface->dev = discover_device_create(network->handler,
 177                                         interface->name);
 178         interface->dev->device->type = DEVICE_TYPE_NETWORK;
 179         interface->dev->uuid = mac_bytes_to_string(interface->dev,
 180                         interface->hwaddr, sizeof(interface->hwaddr));
 181         device_handler_add_device(network->handler, interface->dev);
 182 }
 183
 184 static void remove_interface(struct network *network,
 185                 struct interface *interface)
 186 {
 187         device_handler_remove(network->handler, interface->dev);
 188         list_remove(&interface->list);
 189         talloc_free(interface);
 190 }
 191
 192 static int interface_change(struct interface *interface, bool up)
 193 {
 194         const char *statestr = up ? "up" : "down";
 195         int rc;
 196
 197         if (!up && interface->udhcpc_process) {
 198                 /* we don't care about the callback from here */
 199                 interface->udhcpc_process->exit_cb = NULL;
 200                 interface->udhcpc_process->data = NULL;
 201                 process_stop_async(interface->udhcpc_process);
 202                 process_release(interface->udhcpc_process);
 203         }
 204
 205         if (!up) {
 206                 rc = process_run_simple(interface, pb_system_apps.ip,
 207                                 "address", "flush", "dev", interface->name,
 208                                 NULL);
 209                 if (rc)
 210                         pb_log("failed to flush addresses from interface %s\n",
 211                                 interface->name);
 212         }
 213
 214         rc = process_run_simple(interface, pb_system_apps.ip,
 215                         "link", "set", interface->name, statestr, NULL);
 216         if (rc) {
 217                 pb_log("failed to bring interface %s %s\n", interface->name,
 218                                 statestr);
 219                 return -1;
 220         }
 221         return 0;
 222 }
 223
 224 static int interface_up(struct interface *interface)
 225 {
 226         return interface_change(interface, true);
 227 }
 228
 229 static int interface_down(struct interface *interface)
 230 {
 231         return interface_change(interface, false);
 232 }
 233
 234 static void udhcpc_process_exit(struct process *process)
 235 {
 236         struct interface *interface = process->data;
 237         pb_debug("udhcp client [pid %d] for interface %s exited, rc %d\n",
 238                         process->pid, interface->name, process->exit_status);
 239         interface->udhcpc_process = NULL;
 240         process_release(process);
 241 }
 242
 243 static void configure_interface_dhcp(struct interface *interface)
 244 {
 245         const struct platform *platform;
 246         char pidfile[256], id[10];
 247         struct process *process;
 248         int rc;
 249         const char *argv[] = {
 250                 pb_system_apps.udhcpc,
 251                 "-R",
 252                 "-f",
 253                 "-O", "pxeconffile",
 254                 "-O", "pxepathprefix",
 255                 "-p", pidfile,
 256                 "-i", interface->name,
 257                 "-x", id, /* [11,12] - dhcp client identifier */
 258                 NULL,
 259         };
 260
 261         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
 262                         PIDFILE_BASE, interface->name);
 263
 264         platform = platform_get();
 265         if (platform && platform->dhcp_arch_id != 0xffff)
 266                 snprintf(id, sizeof(id), "0x5d:%04x", platform->dhcp_arch_id);
 267         else
 268                 argv[11] = NULL;
 269
 270         process = process_create(interface);
 271
 272         process->path = pb_system_apps.udhcpc;
 273         process->argv = argv;
 274         process->exit_cb = udhcpc_process_exit;
 275         process->data = interface;
 276
 277         rc = process_run_async(process);
 278
 279         if (rc)
 280                 process_release(process);
 281         else
 282                 interface->udhcpc_process = process;
 283
 284         return;
 285 }
 286
 287 static void configure_interface_static(struct interface *interface,
 288                 const struct interface_config *config)
 289 {
 290         int rc;
 291
 292         rc = process_run_simple(interface, pb_system_apps.ip,
 293                         "address", "add", config->static_config.address,
 294                         "dev", interface->name, NULL);
 295
 296
 297         if (rc) {
 298                 pb_log("failed to add address %s to interface %s\n",
 299                                 config->static_config.address,
 300                                 interface->name);
 301                 return;
 302         }
 303
 304         /* we need the interface up before we can route through it */
 305         rc = interface_up(interface);
 306         if (rc)
 307                 return;
 308
 309         if (config->static_config.gateway)
 310                 rc = process_run_simple(interface, pb_system_apps.ip,
 311                                 "route", "add", "default",
 312                                 "via", config->static_config.gateway,
 313                                 NULL);
 314
 315         if (rc) {
 316                 pb_log("failed to add default route %s on interface %s\n",
 317                                 config->static_config.gateway,
 318                                 interface->name);
 319         }
 320
 321         return;
 322 }
 323
 324 static void configure_interface(struct network *network,
 325                 struct interface *interface, bool up, bool link)
 326 {
 327         const struct interface_config *config = NULL;
 328
 329         if (interface->state == IFSTATE_IGNORED)
 330                 return;
 331
 332         /* old interface? check that we're still up and running */
 333         if (interface->state == IFSTATE_CONFIGURED) {
 334                 if (!up)
 335                         interface->state = IFSTATE_NEW;
 336                 else if (!link)
 337                         interface->state = IFSTATE_UP_WAITING_LINK;
 338                 else
 339                         return;
 340         }
 341
 342         /* always up the lookback, no other handling required */
 343         if (!strcmp(interface->name, "lo")) {
 344                 if (interface->state == IFSTATE_NEW)
 345                         interface_up(interface);
 346                 interface->state = IFSTATE_CONFIGURED;
 347                 return;
 348         }
 349
 350         config = find_config_by_hwaddr(interface->hwaddr);
 351         if (config && config->ignore) {
 352                 pb_log("network: ignoring interface %s\n", interface->name);
 353                 interface->state = IFSTATE_IGNORED;
 354                 return;
 355         }
 356
 357         /* if we're in manual config mode, we need an interface configuration */
 358         if (network->manual_config && !config) {
 359                 interface->state = IFSTATE_IGNORED;
 360                 pb_log("network: skipping %s: manual config mode, "
 361                                 "but no config for this interface\n",
 362                                 interface->name);
 363                 return;
 364         }
 365
 366         /* new interface? bring up to the point so we can detect a link */
 367         if (interface->state == IFSTATE_NEW) {
 368                 if (!up) {
 369                         interface_up(interface);
 370                         pb_log("network: bringing up interface %s\n",
 371                                         interface->name);
 372                         return;
 373
 374                 } else if (!link) {
 375                         interface->state = IFSTATE_UP_WAITING_LINK;
 376                 }
 377         }
 378
 379         /* no link? wait for a notification */
 380         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
 381                 return;
 382
 383         pb_log("network: configuring interface %s\n", interface->name);
 384
 385         if (!config || config->method == CONFIG_METHOD_DHCP) {
 386                 configure_interface_dhcp(interface);
 387
 388         } else if (config->method == CONFIG_METHOD_STATIC) {
 389                 configure_interface_static(interface, config);
 390         }
 391 }
 392
 393 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 394 {
 395         bool have_ifaddr, have_ifname;
 396         struct interface *interface;
 397         struct ifinfomsg *info;
 398         struct rtattr *attr;
 399         unsigned int mtu;
 400         uint8_t ifaddr[6];
 401         char ifname[IFNAMSIZ+1];
 402         int attrlen, type;
 403
 404
 405         /* we're only interested in NEWLINK messages */
 406         type = nlmsg->nlmsg_type;
 407         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
 408                 return 0;
 409
 410         info = NLMSG_DATA(nlmsg);
 411
 412         have_ifaddr = have_ifname = false;
 413         mtu = 1;
 414
 415         attrlen = nlmsg->nlmsg_len - sizeof(*info);
 416
 417         /* extract the interface name and hardware address attributes */
 418         for_each_rta(info + 1, attr, attrlen) {
 419                 void *data = RTA_DATA(attr);
 420
 421                 switch (attr->rta_type) {
 422                 case IFLA_ADDRESS:
 423                         memcpy(ifaddr, data, sizeof(ifaddr));
 424                         have_ifaddr = true;
 425                         break;
 426
 427                 case IFLA_IFNAME:
 428                         strncpy(ifname, data, IFNAMSIZ);
 429                         have_ifname = true;
 430                         break;
 431
 432                 case IFLA_MTU:
 433                         mtu = *(unsigned int *)data;
 434                         break;
 435                 }
 436         }
 437
 438         if (!have_ifaddr || !have_ifname)
 439                 return -1;
 440
 441         if (type == RTM_DELLINK || mtu == 0) {
 442                 interface = find_interface_by_ifindex(network, info->ifi_index);
 443                 if (!interface)
 444                         return 0;
 445                 pb_log("network: interface %s removed\n", interface->name);
 446                 remove_interface(network, interface);
 447                 return 0;
 448         }
 449
 450
 451         interface = find_interface_by_ifindex(network, info->ifi_index);
 452         if (!interface) {
 453                 interface = talloc_zero(network, struct interface);
 454                 interface->ifindex = info->ifi_index;
 455                 interface->state = IFSTATE_NEW;
 456                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 457                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 458                 add_interface(network, interface);
 459         }
 460
 461         /* notify the sysinfo code about changes to this interface */
 462         if (strcmp(interface->name, "lo"))
 463                 system_info_register_interface(
 464                                 sizeof(interface->hwaddr),
 465                                 interface->hwaddr, interface->name,
 466                                 info->ifi_flags & IFF_LOWER_UP);
 467
 468         configure_interface(network, interface,
 469                         info->ifi_flags & IFF_UP,
 470                         info->ifi_flags & IFF_LOWER_UP);
 471
 472         return 0;
 473 }
 474
 475 static int network_netlink_process(void *arg)
 476 {
 477         struct network *network = arg;
 478         struct nlmsghdr *nlmsg;
 479         struct msghdr msg;
 480         struct iovec iov;
 481         unsigned int len;
 482         int rc, flags;
 483
 484         memset(&msg, 0, sizeof(msg));
 485         msg.msg_iov = &iov;
 486         msg.msg_iovlen = 1;
 487
 488         flags = MSG_PEEK;
 489
 490 retry:
 491         iov.iov_len = network->netlink_buf_size;
 492         iov.iov_base = network->netlink_buf;
 493
 494         rc = recvmsg(network->netlink_sd, &msg, flags);
 495
 496         if (rc < 0) {
 497                 perror("netlink recv header");
 498                 return -1;
 499         }
 500
 501         len = rc;
 502
 503         /* if the netlink message was larger than our buffer, realloc
 504          * before reading again */
 505         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
 506                 network->netlink_buf_size *= 2;
 507                 network->netlink_buf = talloc_realloc(network,
 508                                         network->netlink_buf,
 509                                         char *,
 510                                         network->netlink_buf_size);
 511                 goto retry;
 512         }
 513
 514         /* otherwise, we're good to read the entire message without PEEK */
 515         if (flags == MSG_PEEK) {
 516                 flags = 0;
 517                 goto retry;
 518         }
 519
 520         for_each_nlmsg(network->netlink_buf, nlmsg, len)
 521                 network_handle_nlmsg(network, nlmsg);
 522
 523         return 0;
 524 }
 525
 526 static void network_init_dns(struct network *network)
 527 {
 528         const struct config *config;
 529         unsigned int i;
 530         int rc, len;
 531         bool modified;
 532         char *buf;
 533
 534         if (network->dry_run)
 535                 return;
 536
 537         config = config_get();
 538         if (!config || !config->network.n_dns_servers)
 539                 return;
 540
 541         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
 542
 543         if (rc) {
 544                 buf = talloc_strdup(network, "");
 545                 len = 0;
 546         }
 547
 548         modified = false;
 549
 550         for (i = 0; i < config->network.n_dns_servers; i++) {
 551                 int dns_conf_len;
 552                 char *dns_conf;
 553
 554                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
 555                                 config->network.dns_servers[i]);
 556
 557                 if (strstr(buf, dns_conf)) {
 558                         talloc_free(dns_conf);
 559                         continue;
 560                 }
 561
 562                 dns_conf_len = strlen(dns_conf);
 563                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
 564                 memcpy(buf + len, dns_conf, dns_conf_len);
 565                 len += dns_conf_len;
 566                 buf[len] = '\0';
 567                 modified = true;
 568
 569                 talloc_free(dns_conf);
 570         }
 571
 572         if (modified) {
 573                 rc = replace_file("/etc/resolv.conf", buf, len);
 574                 if (rc)
 575                         pb_log("error replacing resolv.conf: %s\n",
 576                                         strerror(errno));
 577         }
 578
 579         talloc_free(buf);
 580 }
 581
 582 struct network *network_init(struct device_handler *handler,
 583                 struct waitset *waitset, bool dry_run)
 584 {
 585         struct network *network;
 586         int rc;
 587
 588         network = talloc(handler, struct network);
 589         list_init(&network->interfaces);
 590         network->handler = handler;
 591         network->dry_run = dry_run;
 592         network->manual_config = config_get()->network.n_interfaces != 0;
 593
 594         network_init_dns(network);
 595
 596         rc = network_init_netlink(network);
 597         if (rc)
 598                 goto err;
 599
 600         network->waiter = waiter_register_io(waitset, network->netlink_sd,
 601                         WAIT_IN, network_netlink_process, network);
 602
 603         if (!network->waiter)
 604                 goto err;
 605
 606         rc = network_send_link_query(network);
 607         if (rc)
 608                 goto err;
 609
 610         return network;
 611
 612 err:
 613         network_shutdown(network);
 614         return NULL;
 615 }
 616
 617 int network_shutdown(struct network *network)
 618 {
 619         struct interface *interface;
 620
 621         if (network->waiter)
 622                 waiter_remove(network->waiter);
 623
 624         list_for_each_entry(&network->interfaces, interface, list) {
 625                 if (interface->state == IFSTATE_IGNORED)
 626                         continue;
 627                 if (!strcmp(interface->name, "lo"))
 628                         continue;
 629                 interface_down(interface);
 630         }
 631
 632         close(network->netlink_sd);
 633         talloc_free(network);
 634         return 0;
 635 }